I swear there is NO YELLOW here (unless you are reading this on a printed sheet):
Yellow is “made” by monitors by emitting red and green lights.
So yellow is a sum of red and green, right? WRONG!
As I said, there is no yellow up there not even as the result of some bizarre sum of red and green. Only ACTUAL red and green. NO YELLOW WHATSOEVER!
Red is the light frequency of 440THz (TeraHertz). Green is 560THz.
Yellow is a somewhat midpoint, of 520THz. Yellow, as you can see in rainbows, is between red and green:
Our eyes are particularly sensitive to Blue (doesn’t matter here) Red and Green. We have receptors for these frequencies, but they catch some of the surrounding frequencies as well. When something in nature is ACTUALLY yellow, its light (520THz) partially triggers the red and green receptors, because their frequencies of sensitivity are close. Our brain interprets that when red and green receptors are simultaneous, partially triggered, this must be the consequence of an actual 520THz incoming light, and it produces a sensation of yellow.
Monitors exploit that phenomenon. They do NOT actually emit any 520THz light, but rather a combination of 440THz (Red) and 560THz (Green) lights, which ends up triggering red and green receptors exactly the same way that an actual 520THz light would, only without the actual 520THz light. And your brain THINKS the receptors are triggered because of a 520THz light and produces the yellow sensation, even though there was NO yellow light at all!
