You could use a three pin two color LED. If your team created the program for the robot, and still have additional output pins for your programmable IC chip, you could just control the two color LED with it and change the light color when the program runs its full cycle or when the task is complete. Now depending on your programmable IC you could also use the RGB LED. Your output pin should then control the current going to the LED to change colors.
Regards,
C. Erbay
http://blog.7pcb.com