Aqua food coloring is available from some specialty baking stores but is not sold by most grocery retailers. The widely available four pack of food colors traditionally includes red, yellow, blue and green. Many different shades and colors can be made by using the food coloring alone or mixing them together in varying combinations and ratios. Achieve the perfect aqua color for a batter or frosting by adding a little food coloring at a time in the correct amounts.
Add four drops of blue liquid food coloring to a small clear glass bowl.
Squeeze in a single drop of green liquid coloring and swirl the glass bowl gently to blend.
Hold the glass bowl an inch away from a light to look through the blend of colors and determine if any adjustments are necessary.
Increase the amount of green food coloring one drop at a time and check the color with the light before changing the ratio. Make incremental corrections with a single drop of blue if the aqua color gets too green.
Apply the aqua food color directly to the food product it is intended to color a quarter tsp. at a time and blend thoroughly until the desired color is achieved.