Each year, I separate out the best photos of the year. For 2010, this photo made the cut. I think it’s because of my chemistry and physics background. Most colors you see in the world are chromatic or chromophore colors. In other words, some chemical compound has loose electrons that absorb certain colors, leaving those you see. However, this device is not about chemistry. It is about physics. The colors are like the colors on beetle wings. The colors come about because of interference in thin layers, giving constructive interference only across a narrow band of wavelengths.
As shown in the picture, physical interference colors tend to be more vivid and pure than chemical chromophore colors. Notice also, the orthogonal color sets all visible on the same wheel: Red-Green-Blue and Yellow-Magenta-Cyan.