Nope…
Okay nope, if I keep doing this I’m going to end up with pink hair or something.
It’s not even that bad, it's actually kind of nice, so, whatever.
Anyway, where did we leave off last week?
Ah okay, I was just about to talk about color, which is a topic I’ve been teasing for well
over a year…
I plan on doing a full episode on color, if not multiple, in the future.
So for any of you Psych majors out there, please don't jump at me for simplifying this
for now.
Alright, so let’s get on with it.
There are ten types of color blindness, the most horrifying is one that I brought up in
the last video – Achromatopsia, or the lack of color vision, this is when you only have
rods.
The wavelengths for rods are very broad, so it basically just amounts to yes there is
light or no there isn’t, there’s virtually no definition and everything appears either
extremely bright or extremely dark.
People who have this often have photophobia, or the fear of light… and hopefully you
understand why, if you had this you probably wouldn’t want to go outside either.
So let’s move out of this nightmare and talk about something a little more reasonable.
Like when the world looks like this.
There are two ways this can occur, the first is called Cortical Achromatopsia, when you
have damage to Area V4, the color center of the brain.
You still have all three cones, so sensation is working just fine but perception is not.
It’s not a hardware issue, it’s a software issue.
But if you only have one cone, it is a hardware issue known as Cone Mono- manachramacy?
*Monochomacy* I really don’t like that term because it’s kind of misleading, it implies
one color when obviously this is no color.
But it’s a way to differentiate between having one cone and having no cones, so…
fine.
Since you’re supposed to have three cones, there are three different flavors to cone
monochromacy.
Red cone monochromacy is the most rare form in humans, but the most common form in the animal
kingdom, especially for low light or nocturnal hunters like dolphins, seals, and ferrets.
Oh no not this again, nope
Can you talk?
Why would he be British though?!
It’s a common myth that dogs only see in black and white.
They don’t, they see in color, because they are dichromats and have two cones.
If you only have one, when different wavelengths of light hit your eye, it excites the cone
cell a little, then a lot, then a little again, and that’s it, so it’s just shades of
gray.
But if you have two, your brain can decipher between a little of this, a lot of this, a
little of this and and a little of that, a lot of that, and a little of that.
And because of that, dichromats can differentiate between wavelengths and therefore see in color.
For the curious, dogs are the opposite of ferrets and only have blue and yellow cones,
they don’t have red.
But speaking of blue and yellow, let’s start with the rarest form of dichromacy in humans:
blue-yellow colorblindness.
Which is… look these names are really dumb, okay?
So we’re going to call it by its more scientific name, Tritanopia, which is the lack of blue
cones.
Each of these dichromat forms of colorblindness also has a diet version, in this case it’s
known as Tritanomaly, which means that they still have blue cones, but they
are shifted more towards green.
So what does the world look like for a tritanope?
Well as soon as I said the name I switched it… so… like this.
This is a normal color spectrum, and this is the same color spectrum for a tritanope.
This might look weird to you because they’re supposed to be missing the blue cone, but
it kind of looks like they’re missing the green cone, and it’s called blue-yellow colorblindness.
Red-green colorblindness is far more common and only men can get it because it’s on
the sex-linked X-chromosome.
Women can get the lite versions, where a cone is mutated, but the odds are so low that it’s
barely worth mentioning.
You have to lose several rounds of the genetic lottery to be a colorblind female.
There are two main types of red-green color blindness and two anomalous or lite versions.
This is Protanopia, and it’s when you’re missing the red cone.
This is as close to what a dog sees as we can get.
Protanopes have blue cones and green cones, but everything looks blue and yellow to them…
everything looks kind of drab because they don’t see red, green, or pu… oh no.
I knew it, I knew this was going to happen… whatever if I just ignore it maybe it'll
go away.
Does this look normal to you?
What number do you see?
Because if this looks normal, and you see any number there at all, like maybe a 2, congratulations,
you have Deuteranopia, which is the lack of green cones.
Again, only men can get this, but it’s the light version of this that is far and away
the most common, with more than all of the other forms of colorblindness put together.
It’s called Deuteranomaly, also known as anomalous colorblindness or color-deficiency
and it’s when the green cone is mutated and shifted more towards red.
Their color spectrum looks mostly normal, maybe a little more brown than usual, but
there are also a few notable colors missing.
And here’s where we can finally start talking about normal color vision, because only when
you break normal color vision down can you really appreciate how it works together.
First, you need to discard most of what you think you know about color, especially if
you learned it in art class.
Light is not paint, and doesn’t work the same way…
like at all.
The three primary colors of light are red, green, and blue, from those you can make just
about every other color.
The monitor you’re watching this on is made up of red, green, and blue pixels.
A white pixel is when all three of them are lit up.
The visible spectrum of light extends from 400 to 700 nanometers, and looks
like this.
The visible portion of the electromagnetic spectrum is incredibly tiny, but we can get
every single color in the visible spectrum with only three cones.
How do you make orange without a yellow?
With red and green.
Oh yeah, well how do you make yellow?
With red and green.
Alright… how do you make purple?
Good question.
Purple is not a real color, it’s a pigment on the color wheel where red and blue meet
up again.
But the visible spectrum isn’t a wheel, it’s a straight line and red never wraps
back around.
There is no wavelength that corresponds to purple, it only exists as a combination and
a conjuring of your mind.
Purple is not a natural color – think about it, what in nature is purple?
Your mind probably jumped to grapes, which, no – they’re called red grapes.
The main reason you think grapes are purple is because purple candy is grape.
Unless you live in the UK where it’s blackcurrant.
Most of you have never heard of blackcurrant, because it’s illegal in the US.
Red and blue are probably the two most important cones you have, they’re so important that
they’re the most common type of opposing color circuit… what do you mean you don’t
know what an opposing color circuit is? …ugh fine.
In your retina, you single cells which are pretty self explanatory, it’s a red cone
that fires when it’s activated by red light or a green cone that fires when it’s activated
by green light.
And then you cells that are connected to each other in opposing color circuits, the most
common type is red and blue.
Stare at the Mona Lisa’s nose while I drone on about how this works.
Right now, blue light is hitting your retina and causing the blue end of the circuit to
fire.
Think of it like a seesaw, it starts out level with the ground, but as more time goes on,
the blue end gets pushed down.
Eventually, the blue end will hit the bottom and your retina will actually start to bleach
out.
If you’ve ever stared at the sky for a long enough time, you’ve seen this happen, where
it slowly starts to fade out to white.
And then, when the weight is suddenly lifted off of the blue end of the seesaw… the red
end fires and you see the afterimage.
I’m sorry, I’m sure that freaked you out, but I totally meant to do that.
If you close your eyes right now, you will still see the afterimage.
So what happens when both red and blue are activated at the same time and the seesaw
is pushed down equally on both ends?
Here are the cone sensitivities for red and blue.
Red’s sensitivity extends far into blue’s.
So what happens here at the end of the spectrum?
Both are activated, so what color do you see?
Purple, or more accurately, violet.
But what about here?
Again, both are activated, but surely, you’re not seeing violet again for a completely different
wavelength.
And you’re not.
This is why you have a third cone, the green cone.
When red and blue are both activated, but so is green, you see green.
When red and blue are both activated, but there is no green, you see purple.
Remember earlier, when I said that deuteranomolous people have some notable absences on their
color spectrum?
I was talking about purple.
Because their green cone is mutated and shifted towards red, there is no point green where
is activated more than red and blue.
So their brain just makes up for that by discarding purple – because purple is a figment of
your imagination – pigment?
Pigment of your imagination.
Anyway, this is an approximation of violet and this is purple.
So how come in pictures of rainbows, the last color is purple, and not violet?
Haven’t you been paying attention?
Because a camera, this monitor, and even your eye, are only made up of RGB.
This color right here is not violet.
It’s a combination of a red pixel and a blue pixel, which tricks your eye into seeing
both red and blue without any green, just like what violet does, so your brain perceives
purple.
I understand that this may be a difficult concept, so the next time you’re able to
see a rainbow in real life, take note of the color after blue, then take a picture of it
and look at the picture – they will look completely different.
So as a trichromat with all three cones, you can see every color on this spectrum, including
colors that are completely made up by your mind, like purple and pink.
They’re not on there.
Which, by the way, is how I know that this is the only genuine video of a guy wearing
those enchroma color correcting glasses…
It's pink!
Yes.
It's pink!
What color's that one?
It's green.
Oh my god, James...
Is this purple?
Yes.
What the f...
So not only are there no repeats along the spectrum, but you see colors that aren’t
even there.
Looking at the cone sensitivities again, anywhere along the spectrum, with three variables,
every wavelength activates cones a little differently.
A colorblind dichromat will have several repeats along their spectrum, because several wavelengths
activate cones in the same way.
A dichromat can differentiate about 10,000 unique colors while someone with normal color
vision can see up to 10 million.
So can a tetrachromat see 100 times more colors than a normal human?
No, pop science articles just write that because the first three cones increase the amount
of perceived colors by an order of magnitude, so surely a fourth must too.
A tetrachromat is something that was blown up by pop science after… after this… here
we go.
A tetrachromat is someone who has four color cones.
But their visible range is still 400-700 nanometers, it’s no bigger than anyone else, they don’t
see any colors outside of the spectrum that a normal person like you or I don’t.
That’s right, I’m not colorblind, I just choose to dress this way.
Oddly enough, there are people who can see outside of the normal spectrum, but they’re
still trichromats.
The lens on your eye filters out ultraviolet light, you can’t see it.
But there are people out there who have had their lens removed and now the filter is gone
so they can see UV light.
What does it look like?
Not like this.
I mean, these are UV lights, but neither the camera nor your eye can see UV, so what is
all this then?
Ultraviolet light is what gives you sunburns these lights will eventually give you a sunburn.
Because these are the exact same lights that are used in tanning beds, but with a purple
party filter.
Why is there a purple party filter?
For the same reason gasoline smells like gasoline, it’s just added so that you know these are
UV lights.
So okay, what does it really look like?
People have described it as a whitish violet… now that sounds like an awesome new color.
Nevermind that it’ll eventually burn your retinas out, that’s something I would like
to see…
So where is their fourth cone?
Here, it’s a yellow cone.
It doesn’t extend the spectrum, it doesn’t add any new dimension that wasn’t already
there.
All of the colors on a tetrachromat’s color spectrum are the same as the normal color
spectrum, there are no repeats, and every wavelength has its own unique combination
of cone activations.
It doesn’t add anything new.
So why did all those people see the dress as white and gold?
I don’t know, maybe it has something to do with why Oklahoma has a panhandle, but
I can tell you what it doesn’t have anything to do with - tetrachromacy.
That stupid dress convinced way too many people that they are tetrachromats because everyone
wants to feel special, so people put out their junk science video or directed you to a color
vision test loaded with ads.
Here’s one from a news website.
How many unique colors can you count on this rainbow?
Go ahead and pause the video and count if you’re so inclined.
But according to the article, if it’s fewer than 20, you’re a dichromat like 25% of
the population.
Nope, I’ve given you the math from real sources, it’s less than 10%.
If you see between 20 and 32, you’re a trichromat – Fine – like 50% of the population – 90%
of the population.
And if you see between 33 and 39 plus, you’re a tetrachromat, like 25% of the population.
Ugh where do I even start.
There are 44 colors on that spectrum, so even if you only get half of them right, you’re
still not colorblind… somehow, whatever.
I know I keep repeating this, but this screen and the pixels on it are RGB, it cannot test
whether or not you are a tetrachromat.
In fact – There is no test you can take at home to find out if you are a tetrachromat.
If I hold up a lemon and look at it, the yellow wavelength hits my retina and activates the
red and green cones.
When you look at this lemon on screen, you’re not seeing yellow light, the pixels are showing
you red and green, which tricks your brain into perceiving yellow.
The only way to test if you are a tetrachromat is to go to a lab, where they will shine yellow
wavelength light into your eyes that will activate a cone more than it activates red
and green… and then that cone doesn’t activate when your eyes are shown the red
and green combination that usually tricks you into seeing yellow.
You cannot do this at home.
So here’s what a tetrachromat can do that you can’t.
This is yellow.
You and a tetrachromat both see this and both agree that this is yellow.
This is also yellow.
You see it and call it yellow, maybe even the same yellow as before?
And the tetrachromat says says hmm… it’s actually ever an so slightly more bluish or
greenish version of yellow?
Oh wow, what an amazing superpower, I’m so blown away that you have this special super
human gift.
You see both colors and just call them both yellow, if you look hard enough, you might
see a difference.
The tetrachromat just has an easier time differentiating yellows.
Do they see more colors?
No.
But they do have a slightly easier time differentiating between two similar colors.
Such epic power.
How many people have that power?
Less than… less?
Fewer.
Fewer than a dozen.
That’s it, fewer than a dozen.
I’m not even going to read that as a percent because the amount of zeroes would just irritate
you.
12% of women carry the fourth cone, but it’s not connected to anything, it’s not in use.
It’s like having a firewire port, it’s just there never to be used.
These are called dormant or non-functional tetrachromats.
Fewer than a dozen women have them connected and in use, and they are known as functional
tetrachromats.
There are no male tetrachromats, functional or otherwise.
It’s genetically impossible for a male to be a tetrachromat, because the fourth cone
is sex-linked.
You can only have four cones if you have two X chromosomes.
So if you’re a guy who thinks you’re a tetrachromat, you’re either misinformed,
lying, or your parents are keeping a terrible secret from you.
Or I guess you’re the first ever, you’re a scientific miracle, congratulations!
Is having more cones really all that beneficial?
Like, what about those animals like the mantis shrimp who have twelve cones?
Do they see colors that we could never even dream of?
Imagine a color you can't even imagine, now do that nine more times, that is how a mantis
shrimp do.
No, they really don’t experience the world as some beautiful colorful place.
Here is the wavelength graph for all of the mantis shrimp’s twelve cones, again, they
are all within the same visible spectrum that we see.
But there’s an additional problem, with so many cones, there are multiple wavelengths
that activate every cone.
At the peaks, they definitely see the color you would expect, but in the valleys it becomes
a muddled gray mess.
A human with three cones can distinguish colors between 1 to 4 nanometers apart.
The mantis shrimp on the otherhand, with its 12 cones, can’t distinguish anything less
than 25 nanometers apart.
So, for example, these two colors – you can tell them apart pretty easily, but a mantis
shrimp can’t.
So is having four cones the next step in human evolution?
No, because it’s not beneficial, you only need three to see the entire spectrum.
It’s also not detrimental, so it’s not being selected out - which is the same reason
dichromats aren’t selected out.
While it kind of sucks that you can’t see purple and everything looks a little more
brown, you can still get around just fine.
I mean, you can’t tell the difference between these two apples, which isn’t too bad, but
if they were berries, that could mean the difference between a delicious snack and a
fatal illness.
Luckily we’re social animals so you don’t have to worry about that too much.
Keen-eyed viewers might have noticed a similarity between the yellow cone of a tetrachromat
and the mutated green cone of a deuteranomalous male, and that’s because they are the same.
You get your red and green cones from your mom, the blue cone is not sex-linked, it’s
a completely different chromosome.
So if you are a dormant tetrachromat female, you have a 50-50 chance of having a colorblind
colorblind son.
If you are one of the 6% of deuteranomalous male, that means your mom is one of the 12%
of non-functional tetrachromats and gave you the mutated green cone.
Just another thing you can blame on your mom.
So is that why some people see the dress as white and gold rather than black and blue,
like it really is?
Because they’re a tetrachromat or a dichromat?
No.
Another theory that was floating around at the time was that people who saw it as white
and gold had a blue color deficiency.
Even if that were true, that would mean that you would always see blue as white.
If I pointed at the sky and asked you what color it was, you’d say white – but you
don’t, you say blue.
Why would this be white, but this still be blue?
Because your color deficiency only affects internet memes?
Having fewer cones does not reduce color perception, it reduces visual clarity.
You see the dress as white and gold because you interpret the background contrast differently.
For whatever reason you take brightness of the background to mean that the dress is a
different color than it really is.
Please, never be an eyewitness, the idea that someone’s life could hang on the fact that
you can’t tell the difference between black and blue or white and gold is terrifying.
So the next time someone tells you that a tetrachromat sees a hundred times more colors
than you, or that you’re a tetrachromat because you see this dress as white and gold
or these shoes as white and pink… not again… hopefully now, you’ll know better.
There you go, the color episode.
Are you colorblind, are you a tetrachromat, or are you just boring like everyone else?
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