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? Let me know down in the comments and don't
forget to colorize that subscribe button. In the meantime, follow me on Facebook and
Twitter, and join the conversation on the subreddit.
Huh, I like this guy.