Egg Yolk Tempera - cooking recipe

Ingredients

1 egg yolk
1 teaspoon water
5 drops food coloring

Preparation

Mix egg yolk and water. Divide into dishes for as many colors as you want to make. Add food coloring to get shade desired (e.g., 2 Red plus 2 Yellow for Orange; 3 Blue for Blue).
Paint on unbaked cookies and bake as you normally would. Cookies will come out with a shiny color finish.