The change from the blue-green color to the red-orange color of Blue crabs was monitored during cooking using a Hunterlab Color Difference Meter set in the L, a, b scale. Changes in the “a” readings were correlated with the changes in internal body temperature. A cooking temperature of 100°C resulted in maximum red-orange color development after 30 sec with no significant changes occurring subsequently. The internal body temperature of the crabs was shown to be only slightly above the initial temperature when maximum color development occurred. The results of this study show that color changes in Blue crab do not serve as an adequate index of proper cooking.