Blue, green and yellow are the dominant colours in these vibrantly coloured crystals. As the crystals move, flashes of the rest of the rainbow can also be seen. (The reverse side of each crystal has a metallic coloured coating which is what gives the crystal it's gorgeous colours.)
These crystals also have a special protective layer designed to protect the effects from scratches, fingerprints and other damage and also helps to prevent moisture damage that can lead to corrosion (example: from perspiration).
