Yes LED lights are allowed on robots.
If you are planning on using the lights just for decoration, (Our team likes to have under-glow on our robot
) the 2015 PCM would be very good at providing a simple on/off power source for the LEDs. {NOTE: this does not work with multicolor LED strips}
However, I do suggest using multicolor LED strips to not only having the LEDs to look very badass, but also to provide feedback to your drivers. (in aerial assist we used the different color LEDs to display shot angle, and flash red if we are about to brown out) The Arduino works very well with controlling this, and this is what we used on our robot. (other controllers are available, but I do not have much experience with them) If you have a spare moment and the programming capability I recommend this highly.