Paste color is also perfect for tinting sugar and coconut. Just add a few drops to a plastic bag and shake. Pastes come in a variety of colors and are capable of creating almost any shade including deep, dark colors. Use a toothpick to apply a little bit at a time. Powdered food coloring is perfect for ingredients that need to stay dry like powdered sugar, or you can brush it on frosting for soft shading.
Marbled cookies are beautiful and easy.
Just tint two batches of sugar cookie dough with different paste colors. Braid them together, roll out and cut shapes. Using egg tempera is another way to create vividly colored cookies. Just blend egg yolk, water, and food coloring together. Paint on cookies with a craft brush before baking.