Lightmo

Lightmo goes well with studying, working, or relaxing, especially in a dimly-lit room. Consider throwing in some new-age music for the premium experience.

If you're running Windows, you can also download the Lightmo screen saver. Simply save it in your /Windows/System32 folder, and Lightmo will appear as one of your screen saver options.

The concept is simple, but procedurally-generated color palettes and modulating gradients provide a continually changing experience.

You can try out the palette generator for yourself over here!