How to Make Purple With Food Coloring

Forget about driving around town or special-ordering the perfect shade of purple food coloring. Mix up a purple food coloring shade fit for royalty by stirring specific amounts of red and blue coloring into your recipe.

White cake frosting, even of the premade variety, is the ideal medium for custom-mixed purple food coloring. Much like working with white paint, stirring in dyes or coloring agents quickly changes the frosting's hue. Because white frosting is opaque, the final result with color added will also be opaque, even though liquid food coloring itself is not. The intensity or richness of the final color depends upon how many drops of food coloring you add.

Both a food coloring chart and an artist's color wheel offer guidance that comes in handy when blending colors to tint a recipe. Red and blue combine to make purple, but the exact amounts of each color needed will vary depending upon both the food coloring brand and the size and type of ingredients in your recipe. For instance, the amount of purple needed to tint a layer cake is not the same amount needed to make soda water purple.

If you're tinting a beverage, use as little food coloring as possible to avoid dyeing guest's lips and tongues purple. The goal for a liquid is a translucent or see-through purple, rather than purple that's so dark it looks black. Food coloring used in a cake batter or icing generally won't cause the dye-transfer issue.

Create a custom purple shade for cake frosting by mixing red and blue food coloring into white frosting. White is required because it is free from other colors; you can't get purple with a chocolate brown frosting, for instance.

Start with 1 cup of frosting, adjusting the ratios upward depending upon your project. A typical two- or three-layer, 9-inch-round cake requires about 5 cups of frosting. One 16-ounce container of store-bought frosting contains 2 cups. When it comes to drops of food coloring, 100 drops is approximately 1 teaspoon.

Create the color of a deep grape taffy with 80 drops blue, 180 drops red mixed into 1 cup white frosting. To make it a darker, more royal shade of purple, stir in more blue, about 10 drops at a time. To intensify the depth of the purple, continue adding in 10 more drops of blue and red, stirring and adding more until the desired shade is reached.

Make a purple shade about halfway between lavender and deep purple by mixing 25 drops blue and 35 drops red into 1 cup white frosting. For a shade quite similar to real dried lavender petals, mix 5 drops blue and 5 drops red into the cup of frosting.

Note: These ratios are estimates, not exact, as the brand of food coloring used will affect the final color. Some colors may be more intense than the same shades created by another company. If you're working with cake or cookie batter, stir in fewer drops of dye at first, keeping the red-to-blue ratios similar to achieve the desired purple tint.

Gel-based food coloring tends to be more intense than liquid food coloring, so it requires far less of both red and blue to achieve purple in your recipe. In some cases, the gel colors are four times as intense as their liquid counterparts. Start making purple by mixing just a few drops each of of red and blue into your recipe. Add more, as needed, to achieve the desired purple intensity.

Blueberries don't create a natural blue food coloring, but they do create a natural purple coloring agent. Add 1/4 cup washed fresh (or thawed) blueberries with 2 teaspoons water to a blender or food processor. Blend until the mixture is smooth, then pour it through a strainer into a container with an airtight lid. Discard the strained skins.

Mix the homemade purple dye into your recipe 1 teaspoon at a time until the desired shade is reached. Store unused portions in an airtight container in the refrigerator for up to two weeks.