Up until a couple of days ago, the only thing I was using colors for was an ili9341-based display.
Several simple color definitions were provided in the custom component for that display. With ESPhome 1.16.0, that display is supported as a standard component, and the predefined colors are gone (except for
COLOR_WHITE, which have been around for a long time).
Well, you don’t want to hear more of my story. I started thinking about ways to provide reusable color definitions without resorting to C++ code. I wanted them to be easily reusable by anybody in an efficient way. Here they are, and can be used by adding a few lines to your existing YAML file. The README gives usage examples. There is a named color definition for everything in the extended colors list of the CSS spec (~140 colors).
(NOTE: a gitlab link, not a github link)