I found an easy way to customize pretty much everything. The trick was to take a screenshot of the interface. Load it in GIMP and enhance or adjust the colors. Then just color pick the new different colors.
I think there is a possibilty to use real time effect filters on the home screen for that cool effect. Maybe we could have OpenGL shaders and filters like in shadertoy as an image overlay.
Here in the example I used the pretty slow GIMP filters. But they could also work.
Just some ideas for the smartphone and for Linux distros.