Oh boy, let me talk about colour theory. This will probably be my least interesting (to anyone else) comment ever.
The human eye has three types of colour receptors, each of which detects the intensity of one specific wavelength: Red (594nm), Green (488nm) and Blue (350nm). Every colour anyone sees is a combination of different levels of those three. For example, if someone sees something that is emitting (or reflecting) no blue light, and twice as much red as green, it will appear to be orange.
Digital colour systems use the same system. If you look very close at your screen, every single pixel is a little trio of lights, one in each primary colour, which can illuminate at 255 gradual levels of brightness in order to replicate any colour.
You can view the impossible colours in this very comic by crossing your eyes until the dots overlap, so that your binocular vision thinks you’re looking at a single square that is both colours at once. Blue and yellow are opposites, since yellow is equal green and red without any blue. Green’s opposite is actual magenta (blue+red) and red’s is cyan (green+blue), but it’s close enough that the optical illusion still works.
Now, as a tangent, you might be thinking that in art class you were taught the three primary colours as red, yellow and blue. It’s not that they got yellow wrong, in this case. What actually happened was that early colour theorists discovered that the primary colours in pigments mix differently than light. In light, the three Additive Primary Colours mix together to create white, while the Subtractive Primaries of pigments make black. The three true subtractive primaries are actually cyan, yellow and magenta (which you may recognize from modern-day printing systems), but back then they discovered it with a slightly darker, cooler blue and a slightly warmer red, and the trio stuck.
Oh boy, let me talk about colour theory. This will probably be my least interesting (to anyone else) comment ever.
The human eye has three types of colour receptors, each of which detects the intensity of one specific wavelength: Red (594nm), Green (488nm) and Blue (350nm). Every colour anyone sees is a combination of different levels of those three. For example, if someone sees something that is emitting (or reflecting) no blue light, and twice as much red as green, it will appear to be orange.
Digital colour systems use the same system. If you look very close at your screen, every single pixel is a little trio of lights, one in each primary colour, which can illuminate at 255 gradual levels of brightness in order to replicate any colour.
You can view the impossible colours in this very comic by crossing your eyes until the dots overlap, so that your binocular vision thinks you’re looking at a single square that is both colours at once. Blue and yellow are opposites, since yellow is equal green and red without any blue. Green’s opposite is actual magenta (blue+red) and red’s is cyan (green+blue), but it’s close enough that the optical illusion still works.
Now, as a tangent, you might be thinking that in art class you were taught the three primary colours as red, yellow and blue. It’s not that they got yellow wrong, in this case. What actually happened was that early colour theorists discovered that the primary colours in pigments mix differently than light. In light, the three Additive Primary Colours mix together to create white, while the Subtractive Primaries of pigments make black. The three true subtractive primaries are actually cyan, yellow and magenta (which you may recognize from modern-day printing systems), but back then they discovered it with a slightly darker, cooler blue and a slightly warmer red, and the trio stuck.