Adam Howard of 3 Sided Cube has developed the MacLight project. It works to vary the color of LEDs mounted behind your Mac to the average color of your monitor. It can also manually set the lighting via an RGB color selector.
Most projects I start are because it’s something that I want for myself. In this case I received a fair amount of interest and opened it up… I stopped development when it worked on my system and suited my personal needs[, and] released it on GitHub so that others can have a headstart if they want to do something similar.