The Practice of Color Mixing 173 surrounded by raw umber. Scenic artists must train themselves to be as analytical and objective as possible when viewing color, particularly when called on to reproduce a color. The eye must be trained to understand the factors that affect perception of color: · Accidental color is the phantom or ghost image of a complementary color that results from a high-chromatic color leaving an impression on the retina. One perceives a color that is not present. An advancing color is a high-intensity warm color that will appear to advance or lie in front of the picture plane. A retreating color is often a cool color but may be any color that appears to recede from the picture plane. Optical mixing occurs when two or more adjacent colors seen at a distance are mixed by the eye to form another hue. A field of blue and yellow dots or stripes will appear green when seen at a distance. Pointillism in the painting of Georges Seurat is an excellent example of optical mixing. Push-pull is the effect that occurs when two high-chroma complementary colors are adjacent to one another. The color fields appear to vibrate or shimmer. · · · ·