This project is a full color LED-controller that can be configured via a USB connection. The color of the connected LEDs (common anode only) depends on the selected operating mode:Slow color change (ca. 40 minutes),Fast color change (ca. 2 minutes),Temperature base color (temperature range adjustable),Constant color 1,Constant color 2.Constant color 3 and Constant color 4.

In the color change modes the color of the LED changes automatically through all possible colors of the rainbow within a certain time.
In the temperature based mode the color changes depending on the temperature measured by the DS1821 sensor.

Temperature based color control

CPU load based color control

Screen based color control

Source: steffenschuette