Switch color of LED when current passed in

Hi All

I am looking at doing a mod for my mouse, basically so when I scroll the mouse wheel, it changes the color of the LED.

i have almost found a RGB LED as they are known, I'm trying to find one with 4 legs. so it will have red, green, blue, and ground.

I need a SMALL circuit that can chage which leg the current is being passed to, when I pass voltage into a seperate line. I don't know if this makes sense, but I would really like to hear from someone who could help me with this.

Thanks in advance,

You beter get to thinking with logic gates...

To do it with transistors can get complicated a lot!
Any how logic gates can get comlicated to but not as lot as transistors.

And here is a noter idea:

Study the circutry of a computer mouse.Meaby you will find the anser.


PS:
I think this project is to comlicated! :?

Here's a good source of LEDs and in particular the tri-color LED you're looking for: http://www.superbrightleds.com/TriColor LED.htm

These guys provide a good service and have fast shipment.