Fading LEDs?

[intosite]

Hi,

I've an idea to do some fasding LEDs to form the rainbow spectum.

I came across a diagram that shows how to do it.http://www.bit-tech.net/article/92/

Now i would like is to be able to use the com to control the fading, eg stopping at a certain color, through the midibox..

Anyone has any idea or experience in this?