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## RGB color trends in NFL team colors

I continue to be fascinated by the RGB color scheme, and extra-spectral colors in particular.  And the NFL football season starts tonight.  And so I ponder: are there any patterns/trends in the official team colors of the 32 NFL teams?  Well, I’m glad you asked.

First of all, here are the “official” colors of the teams with their exact RGB ratings.  You will notice that there are a few teams that, perversely, have more than two team colors.

I’ve already had to make a few judgement calls.  For example, most teams have three team colors: two typical colors, and then either white or black.  In most cases I’ve thrown white or black out, unless they are one of the two main colors (in my opinion).  For instance, the Cincinnati Bengals are orange and black.  I’ve only held onto three colors if I feel they are crucial to their color scheme.  The Dallas Cowboys are particularly meretricious in this regard.  They claim no less than five colors: white, blue, navy blue, royal blue, and silver.  Based on my own aesthetic color sense I have pared this down to three.

Also note that I have renamed the colors in most cases.  Many of the teams copy one another, using the exact same colors, but call those colors by different names.  The most egregious example is the color (0,34,68) which is used by four different teams.  Dallas calls this blue, Denver calls it Broncos navy, New England calls it nautical blue, and Seattle calls it college navy.  I just call it blue.

Only one team has a “pure” RGB color: the San Francisco 49’ers have red (170,0,0).  You gotta give ‘em props for going all-in on red.  I guess (255,0,0) was too “bright” so they darkened it a little, but hey.

So, is there a way to visualize this data in a graph?  The problem is displaying 3-tuples in two dimensions.  Luckily, there is a way to do this.  It’s called a chromaticity graph.  Define three new variables thus:

r = R/(R+G+B)

g = G/(R+G+B)

b = B/(R+G+B)

You can think of these variables as indicating the relative percentage of each core color, without regard to brightness.  So magenta (255,0,255) has values r = 0.5, g=0, b = 0.5, indicating that magenta is half red, half blue.  Similarly, chartreuse (128,255,0) has values r = 0.333, g=0.666, b = 0, indicating that it is 1/3 red and 2/3 green.

Now consider plotting r vs. g.  You might think you’ve “lost” information about the value of b, but that is not the case.  Since r + g + b = 1 is necessarily true, you could always recreate the value of b if you needed it.

Here is a plot of r vs. g, which is a chromaticity graph:

Where you have lost information is in the value of “brightness”.  For example, white (255,255,255), gray (128,128,128) and black (0,0,0) are all plotted at the exact same coordinate (r,g) = (0.333,0.333).  And blue (0,0,255) and dark blue (0,0,128) look very different, but again they map to the same point (r,g) = (0,0).

Note that most of the “standard” colors we have names for appear on the outer edge of the triangle (since one of the three variables R,G,B is zero).  The exceptions are the grayscale colors (white, gray, black) which are at the center of mass of the triangle, and other extra-spectral colors like tan or hot pink.

Speaking of extra-spectral colors: there are two main ways to “construct” them.  You can either:

• mix all three colors R,G,B in roughly equal measure, or
• mix R and B with very little G.

With this in mind, we see that the extra-spectrals occupy the middle portion of the triangle, as well as the bottom edge:

OK, so back to my original goal…visualizing the NFL team colors.  Here is a chromaticity plot of all the team colors in the above table:

What trends do you notice?

• There are plenty of reds, of all varieties.
• All the blues have a major element of green as well.  That is, there is a cluster of colors around azure and cyan, but no true blues.  The blue with the least green is Buffalo Bills blue, at g = 27%.
• There are no true greens.  In fact, there are few greens at all.  The maximum green is g = 57% for the Seattle Seahawks.
• There are no pinks: nothing anywhere close to magenta.
• There is almost a “main sequence” like in an H-R diagram, running from cyan to gray to yellow.  Why do so many NFL colors have g ≈ 33%?
• There is a huge cluster of colors around “gold”.

I’m sure you can find other patterns.  Here is a map of the “under utilized” colors for NFL teams:

The pink/magenta thing makes sense.  For some reason, people think these are not masculine colors.  (This was not always the case.  Pink used to be associated with boys.)  But what about the lack of green?  And the lack of true blue without green?  I have no idea.  Maybe someone can enlighten me.

The Becquerel has me morose;

These units I can’t diagnose.

Don’t measure decays—

But what of equivalent dose?

1 Becquerel = 1 decay/s

There are at least seven units of radioactivity floating around out there, measuring at least three different kinds of things; a veritable zoo of scientific terms. Unfortunately, most people don’t know a rad from a Gray from a Becquerel. Here, then, is my attempt to sort out the confusion.

You’re welcome.

First, let me just say that most people (to my dismay) equate the terms “radioactivity” and “radiation”. There’s some disagreement on the meanings of these terms; I find myself in the conservative camp on this issue. To me, “radioactivity” refers to junk flying out of an unstable nucleus: alpha particles, gamma rays, and the like. “Radiation”, on the other hand, refers exclusively to electromagnetic radiation (anything from long-wavelength radio waves to ultra-short-wavelength gamma rays). By my fuddy-duddy standards, “radiation” is just light; it may or may not be biologically dangerous. Radiation is just one of the possible kinds of radioactivity.

Unfortunately, through the inevitable process of “language creep” (the same process by which the original four “collie” birds became four “calling” birds in the Twelve Days of Christmas, because people are just ignorant) the term “radiation” has come to encompass any ionizing junk from a nucleus.  So some people now call alpha particles and beta particles “particle radiation” to distinguish them from gamma rays, which is “electromagnetic radiation”. This usage bothers me, but I’ll get over it. Just note that I won’t use this terminology here.

So: unstable nuclei exist. They occasionally spit out things—a phenomenon I call radioactivity. These things can often knock electrons free from atoms (i.e. they can ionize atoms). Such ionization events can be detected by a Geiger-Müller tube (among other devices).

Activity. The first way to measure radioactivity is to measure these ionization events in a given amount of time, which in turn tells you how often decays are occurring. So we measure R, the “activity” of a nuclear sample. The metric system unit of activity is the Becquerel (Bq), which is defined to be one decay/second. (Note that 1 Bq is essentially equivalent to 1 Hz = 1 s–1.)

Unfortunately, the Becquerel is a small unit—if we’re talking about radioisotopes used in medicine, for example, we might have to speak of billions of Becquerels. So there’s another unit of activity: the Curie (Ci). One Curie is defined to be the activity of 1 gram of 226Ra. If you want to convert, 1 Ci = 3.7 x 1010 Bq.

There is a problem with measuring activity: it doesn’t really tell you how dangerous a particular sample is. Not all radioactivity particles are the same. Getting hit with millions of weak particles might be preferable to being hit by only a few high velocity ones. One bullet is more dangerous than 500 rapidly-fired marshmallows.

Absorbed dose. To get a feel for the dangerousness of a sample, we talk about absorbed dose: a measure of energy absorbed per kilogram of target material. In metric units, the applicable unit is the Gray (Gy): 1 Gy = 1 Joule/kg. Other people use the rad, with the conversion 1 rad = 1 erg/g = 0.01 Gy. Use of the rad is discouraged by the international scientific community but is still common in (surprise surprise!) the United States.

There’s still a problem. Suppose I’m exposed to 1 Gy of radioactivity (meaning that I expect to absorb a joule of energy per kilogram of my mass). It matters whether I’m absorbing beta particles (say) or alpha particles, because the damage done by alpha particles is worse, pound-for-pound. That is, different kinds of radioactivity are more or less dangerous, depending on the predilection of the given particle(s) for causing genetic damage and possibly causing cancer. This leads us to introduce…

Equivalent dose. Equivalent dose is basically just absorbed dose, times a “fudge factor” that depends upon the kind of radioactivity involved. The unit we use is the Sievert (Sv) = 1 J/kg (weighted). X-rays, gamma rays, and beta particles are all in a sense “equally” dangerous and have a weight factor of 1. So for those kinds of particles, 1 Gy → 1 Sv. Alpha particles, though, are around 20 times as “dangerous”, so if we’re dealing with alpha particles then 1 Gy → 20 Sv.

Of course Americans are contrary when it comes to units, and so the rem is still in common use; 1 rem = 100 erg/g (weighted) = 0.01 Sv. If you’re a science writer, you’d be best served by eliminating rad’s and rem’s altogether; why perpetuate archaic units? You don’t use furlongs/fortnight to measure speed, do you?

I can’t help but mention a seventh unit of radioactivity: the Banana Equivalent Dose, or BED; 1 BED = 0.1 μSv, and so represents an equivalent dose. It (roughly) equates to the amount of radioactive exposure you would get if you ate a banana. (Bananas are naturally radioactive, as they contain significant amount of radioactive potassium, 40K.) This kind of unit helps people put the hobgoblin of “radioactivity” into perspective. “Oh my God! The nuclear plant let off some radioactive steam! Am I doomed?” “Well, your exposure was about 10 BED’s. So basically eat 10 bananas for the same effect.” (There are some issues with the BED as a unit; see this for more information.)

In summary:

Unit                                                     Symbol            Note

Activity

Becquerel: one decay/s                     Bq                   Same as 1 Hz

Curie: activity of 1g of 226Ra              Ci                    Not SI unit, 1 Ci = 3.7×1010 Bq

Absorbed dose

Gray: 1 J/kg                                         Gy

Equivalent dose

Sievert: 1 J/kg                                     Sv

rem: 100 erg/g rem                             rem                 Not SI unit; 1 rem = 0.01 Sv

Banana equivalent dose                      BED                Not SI unit; 1 BED = 0.1 mSv

## Many Worlds Puzzle #3, Solutions

As promised, the solutions…

1.   681472 [Um, Didn’t we answer this one earlier?]

2.   3927.27272… seconds This represents the amount of time it takes the minute hand of a clock to lap the hour hand.  For example, the hands coincide at midnight; they next coincide 3927.27272 seconds later, or at about 1:05:27 AM.

3.   23.14069… This is just e^π.

4.   2.1656 x 10^185 This is how many cubic planck lengths fit in the observable universe…basically, if our universe were a 3D computer, this is how many pixels you’d need.

5.   1.03 light year/year^2 This is the acceleration due to gravity g, in non-standard units.  It has the following interpretation: if you ignored relativity and accelerated at a rate of 1 g (reasonable for a starship), after a year you’d have reached the speed of light.

6.   133956 This is the number of possible combinations of two birthdays, since 133956 = 366^2.  If everyone on Earth had a significant other, there would be over 26,000 couples with the exact same two birthdays as you and your other.

7.   About 19.5 million people The number of people on Earth who share your birthday.

8.   0.739085… This is called the “Dottie number”…an irrational number that solves the equation cos x = x.

9.   1.72048 m^2 The area of a pentagon with sides of 1 m.

10.   0.004295 % This is what percent of Earth’s history homo sapiens has been around.

## The 9 kinds of physics seminar

As a public service, I hereby present my findings on physics seminars in convenient graph form.  In each case, you will see the Understanding of an Audience Member (assumed to be a run-of-the-mill PhD physicist) graphed as a function of Time Elapsed during the seminar.  All talks are normalized to be of length 1 hour, although this might not be the case in reality.

The “Typical” starts innocently enough: there are a few slides introducing the topic, and the speaker will talk clearly and generally about a field of physics you’re not really familiar with.  Somewhere around the 15 minute mark, though, the wheels will come off the bus.  Without you realizing it, the speaker will have crossed an invisible threshold and you will lose the thread entirely.  Your understanding by the end of the talk will rarely ever recover past 10%.

The “Ideal” is what physicists strive for in a seminar talk.  You have to start off easy, and only gradually ramp up the difficulty level.  Never let any PhD in the audience fall below 50%.  You do want their understanding to fall below 100%, though, since that makes you look smarter and justifies the work you’ve done.  It’s always good to end with a few easy slides, bringing the audience up to 80%, say, since this tricks the audience into thinking they’ve learned something.

The “Unprepared Theorist” is a talk to avoid if you can.  The theorist starts on slide 1 with a mass of jumbled equations, and the audience never climbs over 10% the entire time.  There may very well be another theorist who understands the whole talk, but interestingly their understanding never climbs above 10% either because they’re not paying attention to the speaker’s mumbling.

The “Unprepared Experimentalist” is only superficially better.  Baseline understanding is often a little higher (because it’s experimental physics) but still rarely exceeds 25%.  Also, the standard deviation is much higher, and so (unlike the theorist) the experimentalist will quite often take you into 0% territory.  The flip side is that there is often a slide or two that make perfect sense, such as “Here’s a picture of our laboratory facilities in Tennessee.”

You have to root for undergraduates who are willing to give a seminar in front of the faculty and grad student sharks.  That’s why the “Well-meaning Undergrad” isn’t a bad talk to attend.  Because the material is so easy, a PhD physicist in the audience will stay near 100% for most of the talk.  However, there is most always a 10-20 minute stretch in the middle somewhere when the poor undergrad is in over his/her head.  For example, their adviser may have told them to “briefly discuss renormalization group theory as it applies to your project” and gosh darn it, they try.  This is a typical case of what Gary Larson referred to as “physics floundering”.  In any case, if they’re a good student (and they usually are) they will press on and regain the thread before the end.

The “Guest From Another Department” is an unusual talk.  Let’s say a mathematician from one building over decides to talk to the physics department about manifold theory.  Invariably, an audience member will gradually lose understanding and, before reaching 0%, will start to daydream or doodle.  Technically, the understanding variable U has entered the complex plane.  Most of the time, the imaginary part of U goes back to zero right before the end and the guest speaker ends on a high note.

The “Nobel Prize Winner” is a talk to attend only for name-dropping purposes.  For example, you might want to be able to say (as I do) that “I saw Hans Bethe give a talk a year before he died.”  The talk itself is mostly forgettable; it starts off well but approaches 0% almost linearly.  By the end you’ll wonder why you didn’t just go to the Aquarium instead.

The “Poetry” physics seminar is a rare beast.  Only Feynman is known to have given such talks regularly.  The talks starts off confusingly, and you may only understand 10% of what is being said, but gradually the light will come on in your head and you’ll “get it” more and more.  By the end, you’ll understand everything, and you’ll get the sense that the speaker has solved a difficult Sudoku problem before your eyes.  Good poetry often works this way; hence the name.

The less said about “The Politician”, the better.  The hallmark of such a talk is that the relationship between understanding and time isn’t even a function.  After the talk, no one will even agree about what the talk was about, or how good the talk was.  Administrators specialize in this.

If you enjoyed this post, you may also enjoy my book Why Is There Anything? which is available for the Kindle on Amazon.com.  The book is weighty and philosophical, but my sense of humor is still there!

I am also currently collaborating on a multi-volume novel of speculative hard science fiction and futuristic deep-space horror called Sargasso Nova.  My partner in this project is Craig Varian – an incredibly talented visual artist (panthan.com) and musician whose dark ambient / experimental musical project 400 Lonely Things released Tonight of the Living Dead to modest critical acclaim a few years back.  Publication of the first installment will be January 2015; further details will be released on our Facebook page, Twitter feed, or via email: SargassoNova (at) gmail.com.

## Physics is hard!

I’ve had the following conversation at least a few dozen times:

“So where do you work?”

Me: “I’m a professor over at the university.”

“What do you teach?”

“Physics.”

“Physics?  Yikes!  Physics is hard.”

Mathematics and chemistry folks that I know get similar responses.  The unspoken assumption is, why would you want to study something so difficult?

Well, why wouldn’t you?

This leads me to my main point.  When asked why I decided to study physics in the first place, my response is usually “Because physics is hard.”  To me, that’s a sufficient reason.  Not necessary, but sufficient.  I can’t imagine having a job that wasn’t mentally challenging.  Well, unless they paid me enough.

My first exposure to physics (not just science but physics) was in high school, 10th grade I think, when I read a copy of The Dancing Wu Li Masters.  Today I know this book is full of new age nonsense, Deepak Chopra-esque mumbo jumbo, but of course I couldn’t know that at the time.  All I could see at the age of 15 was this great bizarre world of quantum weirdness, and what’s more people were still investigating it.  There was work to be done.  Any copy of Bullfinch’s mythology, or any religious text for that matter, was full of similar bizarre weirdness, but those fields of study seemed static and dead.  But quantum mechanics?  You mean people get paid to think about this shit, and study it in a laboratory?  Count me in!

I was lucky enough to recognize at the time that I didn’t yet have the toolkit for thinking about these kinds of things.  Without a working understanding of calculus, without following the trajectory of physics history into the early 20th century, without seeing the careful, subtle arguments of the physics greats, one can’t really get a handle on quantum mechanics at all.  I wish I had a dollar for every time I met someone who claimed to know “all about” quantum mechanics because they watched a Nova episode about Schrödinger’s cat.  But sorry, quantum mechanics is primarily (arguably entirely) a mathematical theory and as such there are no shortcuts to understanding.  Read as many Brian Greene books as you like…read my book, while you’re at it…but all that can really do is whet your appetite for more advanced study.

That’s what happened to me.  I read a new age book filled with nonsense, but that had enough physics to get me interested.  I wanted to learn more than the author; I wanted to be able to tell him where he was wrong.  (I can certainly do this now.)  And I stuck with physics because it’s maddeningly difficult.

Don’t be afraid of learning difficult things.  Study physics.  Take up quilting.  Learn to play the violin.  Learn how to fix a boat.  Read a book about the Crimean war.  Invent a recipe for Baked Alaska.

If it’s not difficult, then why are you bothering with it?

## Why is there anything?

When I was young, I once looked at a box of cereal and had an epiphany.  “Why is that cereal there?”  A universe of unfathomable complexity, with 100,000,000,000 galaxies, each with 100,000,000,000 stars, making 10,000,000,000,000,000,000,000 possible solar systems with planets around them—all that, and I’m sitting across from a box of Vanilly Crunch?

Since that existential crisis, I’ve always wondered why there was something instead of nothing.  Why isn’t the universe just one big empty set?  “Emptiness” and “nothingness” have always seemed so perfect to me, so symmetric, that our very existence seems at once both arbitrary and ugly.  And no theologian or philosopher ever gave me an answer I thought was satisfying.  For a while, I thought physicists were on the right track: Hawking and Mlodinow, for example, in The Grand Design, describe how universes can spontaneously appear (from nothing) according to the laws of quantum mechanics.

I have no problem with quantum mechanics: it is arguably the most successful theory devised by mankind.  And I agree that particles can spontaneously create themselves out of a vacuum.  But here’s where I think Hawking and Mlodinow are wrong: the rules of physics themselves do not constitute “nothing”.  The rules are something.  “Nothing” to me implies no space, no time, no Platonic forms, no rules, no physics, no quantum mechanics, no cereal at my breakfast table.  Why isn’t the universe like that?  And if the universe were like that, how could our current universe create itself without any rules for creation?

But wait—don’t look so smug, theologians.  Saying that an omnipotent God created the universe doesn’t help in any way.  That just passes the buck; shifts the stack by one.  For even if you could prove to me that a God existed, I would still feel a sense of existential befuddlement.  Why does God herself exist?  Nothingness still seems more plausible.

Heidegger called “why is there anything?” the fundamental question of philosophy.  Being a physicist, and consequently being full of confidence and hubris, I set out to answer the question myself.  I’d love to blog my conclusions, but the argument runs about 50,000 words…longer than The Great Gatsby.  Luckily for you, however, my book Why Is There Anything? is now available for the Kindle on Amazon.com:

You might wonder if my belief in the many-worlds interpretation (MWI) of quantum mechanics affected my thinking on this matter.  Well, the opposite is true.  In my journey to answer the question “why is there anything?” I became convinced of MWI, in part because of the ability of MWI to partially answer the ultimate question.  My book Why Is There Anything? is a sort of chronicle of my intellectual journey, one that I hope you will find entertaining, enlightening, and challenging.

## Many Worlds Puzzle #1

My favorite sort of puzzles are those with no instructions, since such puzzles are very much like doing science.  So without any further instructions, here is today’s puzzle:

Mystery drawing #1

Mystery drawing #2

I dreamed of these diagrams last week, in the middle of the night, much like Kekulé dreaming of the Ouroboros.  I’m hoping a reader can explain them to me!  (Spoilers will be edited.)

## The phantom crane fly

One day in the summer of 2011, while mowing the lawn, I saw a strange creature flying through the air.

Actually, “flying” is too generous a term.  The creature was lilting through the air.  Lurching.  It appeared to have ten legs, and was about the size of a silver dollar.  I was puzzled, to say the least, but that lawn wasn’t going to mow itself so I went back to work.

The mystery bug…

I live in a rural area in the mountains of North Carolina, only 30 minutes away from the entrance to the Great Smoky Mountains National Park.  There’s a lot of wildlife here: I’ve seen bear, elk, deer, raccoons, opossums, groundhogs, voles, and squirrels; our bird feeders are always full of cardinals, chickadees, towhees, finches, and titmice; and I once came home to a 4-foot black snake inside my house.  As for arthropods, I’m very familiar with flies, no-see-ums (family Ceratopogonidae), moths, wasps, honeybees, crickets, ants, beetles, and spiders of all kinds.  I’ve had close encounters with black widow spiders no less than 3 times in my life.

But this thing?  With 10 legs?  Lurching through the air like a drunken hang glider?  Incomprehensible.

Over the course of that summer, I saw such creatures on numerous occasions.  I gradually came to realize that they were insects, since subsequent sightings showed 6 legs, not 10.  My working hypothesis was that what I saw that first day was a mating pair: two of these things stuck together.  But I still had no idea what the confounded creatures were.

In appearance, the insects were bizarre to say the least.  They were striped, like zebras, and their legs appeared  to have at least 3 joints each, so that the legs took on a zigzag character.  They didn’t appear to use their wings, which I guessed were vestigial; rather, picture a 6-legged starfish up on one end, clawing and grasping its way forward.  As a physicist, it looked very much like the creatures were literally swimming through the air.  And so I resolved, with the help of the internet, to positively identify them.

Rutherford said that “all science is either physics or stamp collecting.”  A lot of people take this to be a disparaging comment about sciences other than physics, but I don’t.  I kind of like stamp collecting.  I like being meticulous, and being detailed.  That’s why I like pastimes such as putting together 1000-piece puzzles.

But my search for the identity of the “mystery bug” took stamp collecting to a whole new level.  It literally took me a month of sleuthing to identify the things.  I tried the obvious first: I googled things like “strange zebra striped bug” and “bug that swims in the air” but had no luck.  I posted a question on an entomology bulletin board.  I looked at websites dedicated to “insects of the Appalachians.”

Finally, I had a breakthrough: I saw one of the bugs hitting up against a window in our house.  For the first time, I could see the creature close up and for more than just a second or two.  I verified that the creature did have six legs; I verified that it did have wings, although they seemed useless.  I realized that my mystery bug was a crane fly.  Here’s a more typical, run-of-the-mill crane fly:

A typical crane fly

Regular crane flies are common where I live; kids often mistake them for gigantic mosquitoes (which they are not).

Once I realized that the mystery bug was a type of crane fly, my task was eased enormously.  And eventually I found this assortment of photographs.  Eureka!  I had done it!  They were phantom crane flies, of the family Ptychopteridae.  Specifically, they were the species Bittacomorpha clavipeswhich, according to this Wikipedia article, are “known for the odd habit of spreading out [their] legs while flying, using expanded, trachea-rich tarsi to waft along on air currents.”

It turns out that the phantom crane fly is one of the very, very few creatures on Earth that fly without using their wings.  They are literally swimming, somehow taking advantage of a high Reynolds number (let’s say, 265?) to sludge through the atmosphere without those wings that evolution gave them.  Consequently they look more like seed pods drifting on the wind than they do insects.

What is my point?  I don’t have one.  I just think these bugs are cool, and you should try to find them if you ever visit the Eastern United States.  They hang out in marshy areas in late summer.  Oh, and if you’re a physicist or an entomologist, think about studying these little guys.  The field’s wide open as far as I can tell.  Somebody needs to video the flight of the phantom crane fly, so get on it!  [Note added later: I did find this video which shows the weird flight, are there more?]

## Extra spectral colors, or, why I hate beige.

I don’t want this shirt for my birthday.

What do the colors pink, gray, and beige have in common?

For one thing, they’re all annoying.  I mean, come on…this isn’t rocket science.

But why are they annoying?  Why is lilac (RGB = [220, 208, 255]) so insipid?  Why does jasmine (RGB = [248, 222, 126]) make one vaguely nauseated?  Why is Crayola fuchsia (RGB = [193, 84, 193]) worse than a bout of the common cold?  (Use this applet to investigate these combinations.)

My thesis is this: that these colors are so annoying because they’re extra spectral colors.  And on some primal, instinctual level, humans don’t like extra spectral colors very much.

In a previous post, I talked about how humans have 3 kinds of cones in their retinas.  Roughly speaking, these cones react most strongly with light in the red, green, and blue parts of the visible spectrum.  Now, as I mentioned, “color” is a word we give to the sensations that we perceive.  Light that has a wavelength of 570 nm, for example, stimulates “red” and “green” cones about equally, and we “see” yellow.  That’s why we say that R+G=Y.  That’s why we also say that 570 nm light is “yellow” light.

Extra spectral colors are colors that don’t correspond to any one single wavelength of light.  They are “real” colors, in the sense that retinal cones get stimulated and our brains perceive something.  However, extra spectral colors don’t appear in any rainbow.  To make an extra spectral color, more than one wavelength of light must hit our retinas.  Our brains then take this data and “create” the color we perceive.

In terms of the RGB color code, extra spectral colors are those in which both R and B (corresponding to the cones at either end of the visible spectrum) are non-zero.  And I don’t know about you, but I have a very heavy preference against extra spectral colors.

Now, admittedly, white (RGB = [255,255,255]) is about as extra spectral as you can get.  Does white annoy me?  Not really; but as a color, it’s also pretty dull.  Does anyone paint their bedroom pure white on purpose?  Does anyone really want an entirely white car?

But the other extra spectral colors I mentioned earlier are a who’s who of mediocrity.  Does anyone older than 16 actually like pink?  Has anyone in the history of the world every uttered the sentence, “Gray is my favorite color”?  And beige—ugh.  Just, ugh.

Standard pink has an RGB code of [255, 192, 203].  Surprisingly, there are combinations that are much, much worse.  Hot pink [255, 105, 180] disturbs me.  Champagne pink [241, 221, 207] bothers me.  Congo pink [248, 131, 121] doesn’t actually make your eyes bleed, but I had to check a mirror to verify this for myself.

Beiges are less offensive, but that’s like saying cauliflower tastes better than broccoli.   Of particular note are “mode beige” [150, 113, 23] which used to be called “drab” but was re-branded in Orwellian fashion, and feldgrau [77, 93, 83] which was used in World War II by the German army, in an apparent attempt to win the war by losing the fashion battle.

This is speculation, but I’ve often wondered if these colors bother me because they are stimulating all three kinds of cones in my retina.  Maybe in some deep part of the reptilian complex portion of my brain, I know (on an intuitive level) that these colors don’t correspond to any particular wavelength.  These colors don’t appear in the rainbow.  You can’t make a laser pointer with one of these colors.  You can’t have a magenta, or a beige, or a gray photon.  And somehow, my aesthetic sense knows this.  So when I see the color “dust storm” [229, 204, 201] my limbic system tells me to wince, and I’m saved from even having to know why.

Anyway, I’d be interested in seeing which color(s) bother you the most.  I’m going to guess the color(s) are extra spectral.

[Note: my book Why Is There Anything? is now available for download on the Kindle!]