Color scales have always been a tricky topic. They need to look good, and still represent data. And our eyes have some strange quirks that make colors difficult to get right. Yellow is extra bright for us, and color blindness plagues a significant portion of the male population. We know rainbow color scales do not work well, but how do we design color scales that are good?
First, we should break down what color actually is. The way we biologically interpret color is different from our common mental models. Our eyes have two kinds of light receivers in them. Rods and Cones. Rods are great in low light and for capturing motion, but they don’t see much color. Cones are in the center of our retinas, three kinds that capture red, green and blue wavelengths, respectively. This is why the primary colors of light for us are red, green... keep reading