Colo(u)r ist the topic this time. You are in for a ride from the electromagnetic spectrum to the biology of color vision and the infamous Mantis Shrimp. (Link to the fabulous Oatmeal!) Grassmann’s Law gives a clue how to create a color sensation in the brain by mixing up some wavelengths out of the spectrum. The CIE finally defines what is visible for a “Standard Observer” and Microsoft & HP (sRGB) and Adobe (Adobe RGB) build their color spaces on that foundation. Elle Stone, Bruce Lindbloom and Cambridge in Colour help along the way, passing a Black Body emitting radiation according to Planck’s Law at 6500K just to give us a White Point. Then I organize a shootout between sRGB and Adobe RGB – and I’ll stick to sRGB for the forseeable future. Finally I cover the question of Intent while converting between different color spaces – Perceptual or Relative Colorimetric?