Foxfire is a shimmery glitter Thinking Putty that reveals its true colors with the included black light keychain (in the tin). In a flash, mint green becomes dark blue with an eerie glowing edge. In the dark it glows brightly for over 12 hours. Best played with under regular room lighting so you can see both the daytime and nighttime colors simultaneously! Hold the black light keychain close to the putty to draw a dark line, and move it farther away for a blurry line. What can you do with this new line of Thinking Putty? The possibilities are endless!