I made this recipe myself and my crabs seem to enjoy it and I have seen some enhancement of color. 1. Wash a carrot and cut a small segment into slices and then cut each slice into fourths. (carrots have lots of caratenoids, which enhances color and overall health of the crab along with other vitamins and minerals.) 2. Wash an oak leaf and rip it into small pieces, no bigger than half a dime. (oak leaves contain tannin, which enhances color, and also has health benefits.) 3. Wash a piece of oak bark and break small pieces off of it. (oak bark also contains tannin.) 4. Mix the ingredients together and then there you go!