primary rate interface yellow vs red alarm

And those triads can't actually reproduce all the colors humans can distinguish. RGB and RYB are by no means the only triads you can use. Again, you may not be firing actually yellow light at the person, but if the relative pattern of firing neurons is the same, you'd perceive it as if it was yellow light. You start with no light, and you add levels of various lights until you hit the characteristic pattern of firing cones. RGB (what's used in video screens) is additive mixing. You start with white light, and then take away wavelengths - start with white, take away some wavelengths, and what is left may not actually be photons in the green range of the spectrum, but your eye reacts as if it were. RYB (what you learned in school with paints) is subtractive mixing. So, any mixing plan that hits the same relative combination will get you the same perception of color. You may shine pure dim wavelengths of yellow, and strong pure green and violet, and your eye won't know it isn't actually blue. *Any* light that kicks off your yellow receptors weakly, and the other two strongly, will look 'blue'. Your cones say that your Green and Violet receptors kicked off pretty strongly, and the Yellow weakly, and your brain decodes that as blue. Say a few photons of blue light enter your eye - you don't actually have receptors for blue. The differences between the levels of each that your brain receives can be used to interpret a wide variety of colors. You have three types of cones, which receive best in Yellow, Green, and Violet.

You've got a few different types of photoreceptors in your retina - rods for black and white vision, and cones for color. The roots lie in how your eyes receive, and your brain actually perceives, light.

Primary rate interface yellow vs red alarm