The first science color experiment uses play dough. A simple, no-cook play dough seems to work better when combining colors. For each batch, combine 1/4 cup salt with 1 cup flour. Add 1/4 cup of water and knead the dough to make a clay consistency. Divide the dough into sections and knead in a liquid or paste food coloring. Create enough play dough balls for each child to have two balls, of a different color (for example, one blue ball and one yellow ball). Keep the colors separated at this point. After discussing color combinations, give each child their balls of play dough. Talk about what they think will happen when they mix the two colors. Allow them to blend together until they have a ball of green play dough. They can make a small sculpture and let it dry.