system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5: why are red, green and blue used to "create" other colors? Why these specific colors?
gpt
You might have heard about cones and rods. These are cells in our eyes that send signals to the brain when light is shined on them. Rods respond to most visible light and is responsible for signalling the brightness (black/grey/white). Cones, on the other hand, come in three varieties. One for signalling when blue light is seen, one for green, one for red. Simply put, we use RGB-signals because we can control the balance between those three parameters and easily represent the colours visible to our eyes.