1. With a very sharp paring knife remove the outer green peel of the limes. Slice the peel into paper thin strips and set aside. Slice the lime pulp very thin and remove any seeds. Discard end slices.Measure the peel and the lime slices ( you should have 4 cups) and cover with the cold water.
3. The next day, place limes and liquid in an 8 quart or larger pot over moderate heat and cook, covered, for 20 minutes or until the lime rind is tender. Remove from heat and measure the cooked mixture. (You should have 12 cups.)
5. Boil rapidly, stirring frequently, until the marmalade reaches the jell point. If color is not to your liking, now is the time to add any food coloring (I use the paste food colors when I use any at all because it does not dilute the mixture.)