[header] How to mix light to make colors [title] Gather your materials. [step] You will need three flashlights, colored cellophane (red, green, and blue), three rubber bands, and a white wall. Try to use similar flashlights. 
This will help keep the intensity of each light roughly the same. [substeps] A large sheet of white posterboard or several pieces of white copy paper can be used in place of a white wall.