If you need a soft black to produce black spots for a puppy cake, or you have discovered that only a dead black will do for your next fondant covered Halloween cake, color your fondant with a food coloring. Rather than trying to make a black hue from a mixture of food coloring, use a pre-made black coloring to make your fondant darken quickly as you avoid a sticky mess from mixing colors. Get a true black with a batch of fondant by using simple techniques to blend in the food coloring thoroughly.
Dust a flat work surface with confectioners' sugar.
Place a portion of the room temperature fondant in the center of the work area. Lightly cover your hands with confectioners' sugar.
Using the palms of your hands to soften the it, knead the fondant dough into a ball.
Poke hole on the top of your fondant ball with your finger. Scoop a small amount of powdered black food coloring into the hole. Use small quantities to gauge the value of the hue desired.
Work the color into the dough, kneading with your hands to blend in the black.
Wrap the dough in plastic and allow it to rest for several hours. If the dough does not look dark enough, unwrap, knead into a ball and repeat the process with the black food coloring.
Powdered food coloring has a more concentrated color that liquid coloring and can produce a "true" black.
Wear plastic gloves as you work with food coloring to avoid staining your hands.