To make homemade interior paint, whisk 1 cup flour with 2 cups water, and boil 1 1/2 cups water. After the water begins to boil, add the flour mixture, and cook it until a smooth paste forms. Slowly add 2 additional cups of water to the flour paste, stirring continuously. In a separate bowl, combine 1/2 cup screened clay filler in the desired color and 1/2 cup mica. Gradually stir the clay mixture into the flour and water.
Alternately, make non-toxic finger paint by mixing flour, water and food coloring together. Adjust the flour and water as needed to form a smooth paste, and add enough food coloring to reach the desired color. Another option is to mix shaving cream and food coloring. Spray foam-style shaving cream in a muffin tin, and gently stir food coloring into the shaving cream.
To make textured finger paint, combine 1/2 cup water, 1/2 cup flour and 1/2 cup salt. If the paint is too thick, add more water to thin it. Separate the mixture into plastic bags to make the desired number of colors. Add food coloring to the bags, and squeeze the bag until the coloring is incorporated. Cut the tip off the end of the bag, and put the paint in a squeeze bottle to use it.