The beacon transmission method in vehicular networks has to consider the mobility feature of vehicles and use the wireless channel more efficiently in order to broadcast safety-related beacons with high reliability while respecting strict deadlines. The time division multiple access (TDMA) scheme has been proposed to improve the effectiveness of the IEEE 802.11p CSMA MAC protocol, but it is challenged with access and merging collisions caused by inefficient strategies in allocating time slots and mobile hidden terminal problems. In this paper, we propose colored velocity-based TDMA (CVTDMA), an original colored scheduling scheme for the broadcast of safety beacons on the control channel. Based on vehicles speed and colors that it assigns to time slots according to their occupation statuses, it mitigates the mobility effect and maximizes the reuse of slots while avoiding collisions. The simulation results show that our protocol uses the wireless channel much more effectively than the default one defined in IEEE 802.11p.