In a 1-quart casserole place chocolate, corn syrup, butter and water. Cover.
Microwave at medium for 4 to 5 minutes, until melted. Stir well, until smooth. Prepare
up to 2 colors rainbow pretzels per batch.
Tint chocolate mixture with food coloring as desired. If mixture
becomes firm, microwave at medium for 1/2 to 1 minute, stirring until
smooth and adding a few drops of water if necessary.