“The redness isn’t a property of the apple. It’s a property of the apple in combination with a particular lighting that’s on it and a particular observer looking at it.”
Next to typography, color is the most important part of the visual design of your website. Yet, color is also very misunderstood. Color more than any other part of web design, does not live in a bubble. Color is about how things relate to each other. Saying that #990000 is an easy color to read can change if your background is black, white, or pink
Ensuring that colors contrast correctly means both ensuring that there is enough luminance contrast, but also so that there is enough simultaneous contrast. And if that isn’t enough, we also need to remember to take into account the psychological effect of different colors and the cultural meanings that our color can have.
These four factors combine to make color selection a non-trivial problem. What makes color an even harder problem is that we are only at the type of the iceberg for color perception. What else effects color display? Our screens calibration. The tools we use to change how color display based on the time of day. The cones in our eyes. The lighting in the room.
Color is far from a simple problem. All these factors combine to show why we can’t rush color decisions. They need to be thought out and considered from many angles. As Josef Albers wrote in the seminal Interaction of Color