The resolution of the latest digital display systems, such as high-definition television (HDTV), has increased, making its visual quality a key selling point in the current consumer electronics market. Color transient improvement (CTI) is the process used to reduce the color edge transition time, so that current market demand for the high quality visuals in digital display systems can be achieved. In this paper, we present a CTI method with transient detection and variable length nonlinear filtering that enhances the color edge characteristic of a digital color display system, such as HDTV. The proposed method is based on a transient detection-based CTI algorithm and a variable length nonlinear filtering algorithm. Experimental results show that the proposed method effectively improves the color transient and also solves the problem of the shoots occurring during the CTI process.