In this paper we investigate a method for selectively modifying a video stream using a color contrast sensitivity model based on the human visual system. The model identifies regions of high variance with frame to frame differences that are visually imperceptible to a human observer with normal color vision. The model is based on the CIELAB and the CIE ΔE94 color difference formula, and takes advantage of the nature of frame-based progressive video coding.The method was found to achieve up to 35% improvement in data compression without perceptible degradation of the video quality. As expected, the amount of compression improvement obtained is dependent on the type of video content being compressed.