Do dichromats see medium wavelengths as yellow or green? What colors do dichromats see?

Oct 2017
United States
Do you think this post better belongs in the Environmental History or Philosophy forums section?
Is there a biology or science forum here?

This must be part of the old philosophical question of whether you see the same colors as I do.

This is a simple question, but the description may get a bit technical if your not familiar with basic biology & physics.

It’s important to bear in mind that we shouldn’t equate or compare other animals’ senses & perceptions with our own, such as ‘modified’, ‘enhanced’, ‘dehanced’, ‘reduced’ or ‘increased’ human senses.
We can estimate how the perception of other beings is through study of their brain & sense organ anatomies & behavioral tests, but have little way of proving how they actually experience things.
The same applies to other humans, only that we have more ways of proving how other humans actually experience things because we have language, but even that’s still very subjective.
It’s a basic fact that unlike shape, dimension & location, sensations are not matter & energy itself, but our mind’s representation of them.
This is common sense when mentioned, but many people forget or aren’t aware of this basic fact to keep in mind.

Nevertheless, what I’m wondering is whether the short-medium wavelength dichromats of most mammals & some humans & New World Monkeys, which have two kinds of opsins sensitive to short & medium visible EM wavelengths in constrast to having the extra opsin sensitive to long visible EM wavelength for most humans & anthropoid primates, actually see green or yellow as their primary color representating the middle EM wavelength?

Simulations of dichromatic color vision usually portray them as seeing the primary colors blue & yellow, with the rest being combinations of those primary colors & shades of black, grey & white.
In fact I’ve never come across a dichromatic simulation using green to portray the perception of the middle wavelength color for them.
Its always yellow.
Could it be because we’re not exactly sure whether short-medium dichromats actually see either green or yellow as their primary color for middle wavelength peak, if they even do see those colors for that matter?

However, yellow is not a primary color. It may be in art & design, but it’s not in biology & physics.
Yellow is the extreme end of red & green, & a mixture of red & green.

So what I’m wondering is why do simulations of dichromatic color vision portray the perception of the medium visible EM wavelengths in gradients of yellow rather than green, the actual primary color for middle visible EM wavelength, & how can we know or give the best answer to what color dichromats see as their perception of middle wavelength of Visible EM?

So which color is it? Yellow or green?
& is it the same for all short-medium wavelength dichromats?

How would we know? If we can’t, then what is the best evidence & way to give the best educated guess?

Like why is the dichromatic simulation of the frog & parrots below using yellow & blue to represent their primary colors? Wouldn’t using blue & green be more honest to biology & physics? Isn’t yellow not a primary color but the extreme end of & mixture of both red & green?


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