I need to buy a lighting system that alternates three colors one after another when turned on. Anybody know of anything? Answered

With out more info I'll assume a standard socket light bulb will work.

http://www.amazon.com/Multi-Color-Remote-Control-Color-Changing/dp/B005RZUFBM/ref=sr_1_3?ie=UTF8&qid=1331570305&sr=8-3

That's an LED bulb with lots of colors and options like fade and strobe.

Your not very clear.

Low voltage or mains voltage

How long for

Just show 3 colours one after the other then stop. - go dark or something else.?/

Mechanical or electronic solution.

Lots of questions.