LEDs for decoration

At several competitions from the past year and this year, I have seen several teams using LED strips for decoration on their robot. I have been searching online for LED strips, but I am having a hard time finding anything. I believe that my main problem is the power source for the LED strip. I am not sure of what I should be looking for that would be legal for competition (assuming the strips are legal to begin with.)

If anyone could post links to examples of LEDs that you have bought in the past, it would be greatly appreciated!

here is what we used at competition a few times. It runs normally on 3AA batteries, but we wired the battery pack using the power wires from a sensor port to power the lights.

Thanks man!