help in creating a colouring robot

[VineetKakati]

Hi guyz...I am supposed to do a project which involves colouring regular shapes...the project consists of swarm robot tech with each robot having a different coloured marker ..a digital image like 3 diff colured circles is given as input via pC....robot must recreate image with each robo colouring proper circle...I hav got down the drawing part covered...can  anyone provide me a resource describing how to implement colouring shapes........the robot being used is the spark 5
http://www.nex-robotics.com/products/spark-v-robot/spark-v.html