Try these bright color gels instead of the liquids you buy from the store.  You will be amazed.  These are concentrated gels; just a drop from the easy-squeeze bottle will do.  And the colors are brighter and prettier than what you have seen before.  

Each bottle contains 3/4-ounce color gel, larger than many of the store liquids. 

Even if you only occasionally decorate cookies or cakes, you still use colors.  Now you can use more colors, easy colors without spending a lot of money.  Actually a bottle of these gels, costs less than the inexpensive liquids do in the stores.  And because they are concentrated, they will last much longer. 

1. Start with enough icing to cover the entire cake.  Matching shades later can be difficult.
2. Dip a toothpick into the food coloring gel and then dab it or squeeze a single drop into the icing.  Add a little more until you get the right color. 
3. If you use a new toothpick each time that you add color so that you do not get icing in your food coloring jar. 
4. Deep colors such as red may take more food coloring to achieve.  To use less coloring for black and brown, start with chocolate icing. 
5. Don't get your icing too dark.  Color tends to deepen over time.
6. Royal icing often takes more food coloring than buttercream to reach the same shade. 

Note: If you use these gel colors instead of liquids to color sugar crystals, mix a dab of gel with a drop of water on a spoon and then stir it into a cup of sugar crystals.