Of course, samples of tile, stone, wood, and paint that seem to blend perfectly when spread out on a showroom table inevitably look different at home in varying natural and artificial lighting. “It’s a jigsaw puzzle,” Smith says. “What makes it work is the good lighting, the good paint, and all of those elements and colors blended together.”

Consulting with a designer can help you customize a room’s palette, open up new resources, and solve potential problems. For example, as your eyes age, colors don’t seem as bright. A pro’s eye can keep your changing vision from compromising your design vision. Or, if you have a flow-through kitchen—one open to a family room or great-room—you may need help coordinating the colors inside the kitchen with those beyond to avoid jarring or stopping the eye.

More than the size or shape of a room, the amount of natural light and the kind of artificial light used can impact color choices. For example, a bath in soft blues and greens may look great in morning light, but the colors can turn dull under incandescent light. “Daylight enhances lively colors, but the absence of daylight, in my opinion, calls for warmer, softer color schemes,” says Kennedy, who often recommends color-corrected fluorescent lighting. “There are blues that can go very cool and look great with white, or there are blues that can be a wonderful complement to warm, rustic pine. The most successful rooms do have that balance, that blending of the warm and the cool.”

Never pick countertop granite from a small sample, the pros advise. Instead, “Go to the granite yard and put your template on the slab,” Smith says. “It makes such a huge difference. You may have a beautiful vein that has some quartz in it, or you may have a dark area. It’s an extra step, but by placing it right where you want, it pays off.”

When choosing cabinets, treat wood like any other color. Paints, stains, and glazes can create limitless color options, and finishes can easily be tweaked to blend with other elements, making wood tones one of the most flexible parts of a color palette. “Wood tones don’t have to be brown,” Kennedy says. “They can be anything from blue to orange. They can be cool, misty, silvery gray. Even browns range from cool to warm.”