In RoboCup games, accurate perception is the key to winning a game. Meanwhile an accurate color segmentation is crucial in accurate perception. The previous color segmentation methods either too time-consuming, or can not deal with uneven light or light changes. In this paper, we proposed a real-time robust calibration-free color segmentation method, which can cope with uneven light and lighting condition changes, and calculates the ranges of each color fully autonomously. Full algorithm and procedure has been given in this paper. Experimental results show that the proposed method is real-time, robust and effective.