My idea is simple.
I was wondering. Or really I figured out an easy way to change colors of themes by chance.
I wanted to present some text but with some cool GIMP filters.
Said an done. After I wanted to see what glow looked like for text. I tried some other filters.
Hmm. Here presents itself a very easy way to change the color of everything you want in an easy way. I mean. Why change a color at a time when a filter will change all the colors for you to your perfect liking.
So if you like to code and want to change colors to your preference why not try GMIC and the other standard filters in GIMP. Then just use a color picker to select the new improved color choices.
Some examples of filters could be tonemapping, detail filters and more. You can use other software than GIMP. Like darktable or rawtherapee.
This reminds me. A wanted feature of GIMP would be the blender spacebar search popup window. For finding the filter that is.
Maybe css for HTML5 web pages should have color filters also for added functionality and readability or coolness.