Everyone's photo receptors in our retinas CAN be different. But the only colors we would see different are red, green, and occasionally blue. So were all fine. My purple is still yours.
That's bullshit I'm afraid. Colours correspond to different wavelengths of light and that is what the receptors detect. Red is always a certain range of wavelengths, like blue is always a certain range of wavelengths. The receptors convert these wavelengths via reactions with photopigment in the retina and this forms a certain, specific electrical pulse signal sent to the brain, and due to the fact that everyone's (humans at least) photoreceptors are identical, the nerve impulses created will also be the same (same frequency). When these pulses reach the visual cortex, they are converted into the perception of colour in the brain. Each wavelength of light produces a consistent nerve impulse frequency between people, as seen in brain EMG studies. This is a very brief descritpion of the process, but in conclusion we all see colours the exact same way. The only difference may be between men and women; who can see more shades of red than men, but it is still just red.
Like when the little shit started to get all horny only because the girl's hair was red. No?
Oh.... How?....
WHAT