Learners experiment to see which colors of light will cause a phosphorescent (glow-in-the-dark) material to glow. Different colors of light have different wavelengths, and different amounts of energy. Only the colors which shine with sufficient energy can charge up the phosphorescent material enough to glow in the dark. This activity starts on p.26 of the manual. This manual contains four activities related to the Spectra: The Original Laser Superhero Force comic book published by the American Physical Society.