Colors and a Tornado

Ok, I’m relatively new to OpenGL…I’m in a class in college for OpenGL. Our first project is to create a “tornado” (upside down cone" which has a particle revolve around it. This particle is supposed to cycle its color from whatever to whatever from the top of the cone to the bottom, and then back again. Anyone have any suggestions as to how I can accomplish this and make it look really cool? Like maybe add a cloud texture or something?

Any ideas, examples, etc would be greatly appreciated…

Thanks
Jeremy
Daytona Beach, FL