Color Contrast II lets visitors test their color sense, and demonstrates how color perception is easily influenced. A monitor screen displays two large squares of different colors, each of which contain a smaller colored square in the center. A control allows the visitor to adjust the color of the small squares until they appear to be the same. A second control checks whether the squares are in fact the same color; often they are not. The background color of the two larger squares, as well as the colors of the smaller squares, can be changed.