Stained glass, mosaics and Pennsylvania Dutch stencil designs are other good examples of this principle at work. Value contrast sets the tone for color expression. Full-contrast artwork has a complete range of values, from white through midtones to dark, and suggests normal illumination. Middle values usually provide the framework for value painting, with light and dark value contrast giving the work its visual impact. High-key colors, the tints and middle tones at the light end of the value scale, are usually pure colors and convey a feeling of soft, harmonious ambient light.
Artwork using high-key color is cheerful and optimistic.
Low-key colors in middle to dark values indicate dim illumination, and create a serious, pensive mood. Intensity contrast comes from placing pure, bright color within areas of grayer, low-intensity color. Bright colors or pure tints surrounded by a field of neutrals sing, especially when the hues are complementary. For example, red seems much brighter when the gray next to it is tinged with green. J.M.W. Turner was a master at using pure, delicate tints next to low-intensity colors.