In order for the robots to control their position, they must first have some capability of sensing the distance to each of their neighbours. In many configurations, the identity of each neighbour is also essential to determine. A camera-based identification and tracking system that performs this necessary sensing was devised and implemented. The syste involves a circular sequence of colours around the perimeter of each robot. To maximise the number of possible robots while guaranteeing that they still can be identified, a combinatorial model of the colouring process was created. Interesting links were found to cycle decompositions of de Bruijn graphs, and several existence results were proved using a combination of Galois field algebra and combinatorics of words. The mathematical constructions that led to these results were developed.