Comment by circlingthesun

There is a related video by minute physics about how the RGB color space stores the square root of the brightness of each color channel, because human color perception is roughly logarithmic. Bad color blending is therefore pretty commonplace because it uses the average of square roots instead of the square root of the average of the original brightness values. See: https://www.youtube.com/watch?v=LKnqECcg6Gw