You see colour using three different kinds of cones in our eyes, and these cones can be either red, blue, or green. So where does yellow come in? Green consists of yellow and blue – but how would you only see yellow and not the blue that would make it green?
In: Biology
You are right that there are three types of cones, L, M and S. And these are centered around different wavelengths and therefore different colors. But it is not red blue and green. This is what we use to make artificial colors. It is more purple, green and yellow. But each type of cone detect colors in a wide band and there is even lots of overlap. So even though the M cones are centered around green they still register about 70% of the yellow light. Your brain just translates that when there is more signal from the L cones then the M cones the light is yellow and when there is more signal from the M cones then the L cones the light is green. When there is only signal from the L cones the light is red because the M cones can not see much red at all. This is why we use red LED lights when making artificial light as we can trigger only the L cones. So what we can do to make it appear yellow is to combine a green and red light which will fool your brain into thinking there is a yellow light.
Latest Answers