In one embodiment of the invention, photo-chromic toys are disclosed. A photo-chromic toy includes a photo-chromic material such as a photo-chromic ink, paint, plastic, or dye. The photo-chromic material may be supplied in a material of the toy or applied to a surface of the toy at the factory. The photo-chromic material may be activated in various ways with various light activating devices that can generate the activating light with appropriate wavelengths.