you can buy the leds from e-bay sellers by the 10s or 100s, from hong cong, or a few us sellers resale them for more money
they are really cool when it comes to voltage, pretty forgiving, you can shove about 4V max into them, they run on 3.6V very nicely. and when the voltage drops the blue, then the green slowly drop out.
basically as one might expect, when the voltage gets low, the led gate that takes the most voltage dims first.
and the curcuit keeps on going, so at the end of the battery life (or voltage) the thing is still cycling, but only the red lights up.
runs great DD off of a trio of ni-mhys, i was using AAAs on a 11 string, and the current to them was just about right.
i hope that splains it.
they come in fast changing, which changes very discoey, the rapid change stands out, and can become obnoxious.
and in slow changing, so slow that it could be called mesmerising, or boring, or meditative.
the Pattern of change is very sofisticated, its not just flashing but going through a series of types of pattern changing. rather amasing set of leds.
if your thinking of stringing them on your xmas lights, i figured from the fluxuations in power (current) it does would make it unusable in a series string, so if you want a string of them your probably stuck stringing them in parellel , which works great. (that means they probably will NOT work in ANY of the average 120v Xmas string lights without major modification of the string somehow)
because each is slightly different, a string of them will only sync or chace for so long, so basically they are all on thier own, each doing different things.
let me see if i can find you a seller
http://search.ebay.com/search/searc.../ws/&fkr=1&from=R8&satitle=rgb+led&category0=
try that, that usually find them.
remember there is Fast ones and slow ones, and they are very different speeds.
i think i also saw they have them in milky too not just clear.
ya know while i am rambling here
the things actually do make white light during thier cycling by lighting all three of the colors, although each emitter is offset , i am surprised they dont make a rgb "white" that doesnt flash using this same method.
(most rgb leds have to be powered seperate)