In this paper we present a low-cost colour vision system mainly intended for robot design competitions, which nowadays is a popular, project-oriented, way of teaching mechatronics in engineering curriculums. The estimated cost is about 450 dollar inclusive colour camera and the system is small enough to be carried on-board relative small mobile robots. The system is build around a signal processor TMS C31. We also present and discuss the experiences made with the system in our robot design competition.