A successful painting is not simply a well-designed depiction of a pleasant subject any more than a successful novel is a grammatically correct description of an interesting event. Good art requires more than that. The artist must convey his personal response to the subject and direct attention to the important elements. One way to do this in painting is by planning the placement and degree of contrast. This would be much easier if the three kinds of color contrast — value, intensity, and hue — were equally attractive to the eye. But they're not.

Value contrast is the color quality that most strongly attracts our eye. And we greatly prefer light objects to dark ones. In the top illustration, the white object is the first thing to attract our eye. One problem: although white strongly attracts the eye, it rarely rewards it. For example, we probably wouldn't marvel at the beautiful whites in a Monet garden painting. We'd find the pinks, yellows, and blues far more exciting. So don't feel compelled to always leave whites in your painting or to employ them to create focus.

Intensity contrast does not have the power of value contrast. It's much more subtle and can easily be overpowered by strong darks and lights. However, when the values in a painting are fairly close, our eye prefers "cleaner", more intense colors to "dirtier" or more neutral ones. In the middle illustration we immediately seek out the intense yellow object and the bright, clean top area of the bottle.

Hue contrasts are also more subtle than value contrasts, but when the values in a painting are fairly close, we're attracted to adjoining areas of complementary color. Generally, we prefer warm colors to cool ones.

Applying this information
All very interesting, but how do you use this in a painting? You employ these contrasts (but rarely all three in the same painting) to attract and hold the viewer's attention, to direct it to areas of importance throughout your design, and to express a personal emotional quality. Understanding the effect of these qualities will help you envision the effect you want.