rota is right and bree is right. what they dont realize is they are talking about two different things.
internally the color is consistent for color blind and color sighted
the in consistency lies in what the two groups of people see.

the reason for it is the addition or subtraction of a vision lens (depending on which group you fall in) some where along humanities rode to humanity (we can argue who/how later) a third color receptor was mutated into our vision. as with all mutations what isnt used is discarded. so it can be argued that the humans with color blindness are evolving away from the need to see color or it can be argued that humanity is still trying to make up its genetic mind about weather color vision is a useful tool.
i would love to see (pun intended) what the world would look like with a forth color receptor added to our vision.

the reason that the primary colors are red, blue, and green, is that those are the color receptors in our vision. the people with color blindness dont have the color receptor red. because red was the new one we got.

what i wonder and may never know is: what would the fourth color be