I can tell you that the grid is more physically uniform than perceptually uniform. If they're Munsell colors, as the article suggests, they should be close to

I can tell you that the grid is more physically uniform than perceptually uniform. If they're Munsell colors, as the article suggests, they should be close to perceptually uniform. The Munsell system was specifically designed around perceptible color differences: https://en.wikipedia.org/wiki/Munsell_color_system https://en.wikipedia.org/wiki/Munsell_color_system It's pretty old, so it predates any of the modern standardized color systems you'd typically use in software today.