You can achieve the color brown for food coloring in many different ways. One technique is to blend existing food colorings together. Another technique is a more natural process. Either way, the result will be similar.
Things You'll Need
Mix equal parts red and green food coloring.
Vary the amount of each color to achieve the desired shade.
Add additional color for more specific shades. For instance, adding a touch of orange and green will create a tan-like brown, while a warm, rich brown can be achieved by adding a touch of yellow. If the color looks too gray or black, add more red or yellow.
Put 1 cup of instant coffee in a glass or enamel pan and add 1 cup of water.
Place the mixture over medium-high heat and bring to a boil.
Turn the heat to medium and simmer for 30 minutes.
Remove it from the heat. Cool and strain the mixture wiht a very fine-mesh strainer or coffee filter. Make sure no grounds fall through.
Cocoa and Tea
Follow the same method for making brown food coloring from coffee, but use 1/2 cup of cocoa or 10 teabags instead.
Omit the straining step; there are no grounds to strain out.
Understand that the color or shade of brown will vary.