Glaciers often appear to glow with shades of blue, purple, and green light. This is because they absorb the red, orange, and yellow light delivered by the sun. The remaining higher spectrum colors change depending on the ice thickness, trapped air bubbles and the angle of the sun. Combine these colors and you have the magical glow that inspired Mystic Glacier. An icy blue swirled with glitter, this Thinking Putty glows green in the dark and turns a deep purple with the included Glow Charger™.