And make sure to use LAB color space! https://en.wikipedia.org/wiki/Lab_color_space https://en.wikipedia.org/wiki/Lab_color_space In LAB space, the distance b

And make sure to use LAB color space! https://en.wikipedia.org/wiki/Lab_color_space https://en.wikipedia.org/wiki/Lab_color_space In LAB space, the distance between two colors approximate perceptual distance (how different two colors look). Its not exact---it can't be, because the space isn't actually Euclidean---but it's close. RGB, on the other hand, isn't close. Here's a visualization of RGB space embedded in LAB space: https://en.wikipedia.org/wiki/HSL_and_HSV#/media/File:Srgb-in-cielab.png https://en.wikipedia.org/wiki/HSL_and_HSV#/media/File:Srgb-i... If RGB space corresponded to what our eyes saw, that would be a hexagon.