Gently place eggs in single layer in large saucepan. Add enough cold water to cover eggs by 1 inch. Cover. Bring just to boil on high heat. Remove from heat. Let stand 12 minutes. (Adjust time up or down by 3 minutes for each size larger or smaller). Pour off hot water and rapidly cool eggs by running them under cold water (or place in ice water) until completely cooled. Mix 1/2 cup boiling water, 1 teaspoon vinegar and 10 to 20 drops food color in a cup to achieve desired colors. Repeat for each color. Dip hard-cooked eggs in dye for about 5 minutes. Use a slotted spoon, wire egg holder or tongs to add and remove eggs from dye. Allow eggs to dry.