| Purple Material. Place a piece of purple material by clicking on the purple Material button and then clicking in either the Material A Region or the Material B Region. To see how the percentage of incident light reflected by purple material varies by color, click the Open Material A Graph or Open Material B Graph buttons. To see the spectrum of light from a particular source reflected by purple material, use the Spectroscope tool. To model the reflection by a "perfectly" purple material, use the Ideal Material tool.