Coloring almond bark, an artificial form of white chocolate, can be challenging, especially if you're using water-based food coloring. If you've heard the expression that oil and water don't mix, it's true – almond bark is made primarily with vegetable oil and fat and thus makes it incompatible to use with water-based food coloring. By slowly melting the almond bark and using an oil-based food dye you can color your white almond bark a variety of shades with little hassle.
Unwrap your white almond bark, decide how much of it you want to melt, and use a knife to chop up the bark into small slivers and chips. The smaller the pieces of bark, the faster and more evenly it will melt.
Melt the bark either by stovetop or by melting it in the microwave. To melt on a stovetop, place the chopped up bark into a double boiler over medium heat and stir constantly until melted. If you don't have a double boiler, fill a large kettle ¾ full of water and then place a medium-sized kettle inside the larger one so that it's floating in the water. Put your almond bark into the medium kettle and heat with high heat. If you want to melt your bark in a microwave, place your bark chips in an uncovered microwave-safe bowl and heat in 30-second intervals, stirring every thirty seconds until bark is completely melted.
Add the oil-based food dye to the bark as soon as it is completely melted. Add one drop of the dye at a time until you've achieved the desired tint, stirring thoroughly after each drop. Your bark will now be ready to use. When the bark starts to harden up, or if you decide to add more food dye later, repeat step 2 to re-melt the bark.