Actionscript? I don't know. How would I?

I have this flash and I want these bursts of colors to come up on screen, expand, and then fade away.

I’ve got that part, but looping is boring!

However, is there a way for it to randomize which of the colors, how long the burst is, and how big the burst is as well as when it happens?

I’m doing this in Flash 8 (The samples were made in Flash 6, I know)

Thanks!