I built a motor out of two paper clips, some wire, a magnet from a Levitron™, and a 13.8 volt power supply. Here's a speeded-up video of the construction...
This is an old test I did last summer, using a PIC microcontroller to produce various colors on a 3-element RGB LED. Just like colors on a computer screen, any color can be reproduced (more or less) by varying the brightness of the Red, Green, and Blue elements of the LED. This is done by the PIC 16F84A microcontroller, using pulse-width modulation.