Whether it's Jerusalem limestone or Pennsylvania slate, stone is the most popular flooring today, says Jennifer E. Wilson, a spokesperson for Lowe's. And because the flooring material is often more dramatic than a white toilet or tub, it is important to consider the hues underfoot when choosing paint for the walls.

But that doesn't mean matching the color exactly, says Margaret Walch, director of The Color Association of the United States. "If you try to match a natural material like wood or stone exactly," says Margaret, "it always comes off as lesser." Instead, she says to use the natural color as an inspiration for a second shade that will create a harmonious, but multi-colored look.

"Many people put plants in their bathrooms," notes Margaret. "This paint color allows you to have a mix of natural green and manmade green."

But remember that natural colors needn't just be green and tan, says Joan Osburn, of Osburn Design in San Francisco. "Earthy colors really include not only the greens of grass and trees," says Joan, "but also flower colors in every hue."