Color is one of the major influences on a room's mood, and paint one of the cheapest ways to dramatically alter it. "You can change the room from something you maybe didn't like to something you love," Christine Frisk said. So if you find you're not crazy about a color once you've covered your walls with it, don't "punish yourself" by forcing yourself to live with your mistake for years -- just go ahead and repaint, Ryan Thuftedal urged.DON'T WORRY ABOUT TRENDS -- EXCEPT MAYBE TO AVOID THEM.

"Almost all colors are in play these days," Thuftedal said. Always loved teal or orange? Have a favorite painting with a lot of reds and browns? Forget the Hot New Colors for Spring and just go for colors you like. If anything, avoid shades designated as trendy, as they're the most likely to look dated in a few years.

Some colors, such as grays, off-whites and other muted colors, are popular in every era, Thuftedal said. Colors found in nature are popular lately, said Laura Bischoff, reflecting a cultural move "toward less excess and environmental consciousness."

PAINT-CHIP SHADES WILL LOOK MORE INTENSE WHEN EXPANDED TO COVER A WALL.

People sometimes get fooled because they hold the paint chip horizontally under a light, which lightens the color, rather than vertically, as it will appear on the wall, Thuftedal said. When considering a strip of chips, he suggests avoiding the three boldest colors on a strip: "Pick a color and back off a couple of steps." Especially when working with more intense colors, many designers recommend buying a small sample of the paint and painting a large board or portions of the walls themselves. Try the color on both a wall next to a window and a wall opposite a window. "Daylight will wash out color," Frisk said. "I prefer looking at color on a cloudy day."

AN ACCENT WALL PROVIDES BALANCE AND FOCUS.

A wall that's a different color than the other walls draws the eye, Thuftedal said. Even if darker, it appears to come forward, making it a good way to visually shorten a long, narrow room, he said. Accent walls can also be used to highlight architectural details, windows, fireplaces. When in doubt, Thuftedal suggested, pick the wall you face when you enter a room.

PICK COLOR THAT WORKS WITH THE ROOM'S EXISTING FEATURES.

Hold paint chips next to the floor and the woodwork. "Every color looks good with white trim," Andrea Dixon said, but unpainted wood can be trickier. The golden oak often found in ranch or suburban houses, for example, can give paint colors a greenish cast. She and Jen Zieman have a term to describe kitchens combining golden oak cabinets and yellow walls: "peanut-butter kitchens." Architecturally interesting walls, or walls with lots of beautiful art work, don't always need much color, whereas walls that lack architectural details are "kind of screaming for a dramatic paint color," Zeiman said.

CONTRASTING COLORS CREATE ENERGY, WHICH MAY OR MAY NOT BE A GOOD THING.

Not everyone realizes it, Laura Bischoff said, but the level of contrast between various colors in a room can be as important as the colors themselves. A recent trend toward high energy, high-contrast colors (the slate and bright orange pairing in Bischoff's own home, for example) is "dying off a little" in favor of softer, lower-contrast combinations such as the aforementioned muted natural colors. High contrast adds to the "energy level of a room," she said, whereas lower contrast produces a "natural, unified, uncluttered, calming space."

REMEMBER THAT THERE ARE LOTS OF DIFFERENT WHITES.

Frisk makes sure to use the same white on the trim and the ceiling (typically, the ceiling paint is flatter). "I don't like a bunch of different whites mixing in a space," she said. But she doesn't view white as mandatory for a ceiling. She likes using sky blue, light green, gray, even pink -- depending in part, of course, on the colors beneath it.

KNICKKNACKS.

• "Powder rooms are like a little bit of jewelry," Frisk said. They're a good place to try a bold color that might be over the top in another room.

• Like to switch accessories with the seasons? Choose neutral colors for the big stationary items -- walls, rug, furniture -- so that blankets, pillows, glassware and even curtains in different colors can stand out, "rather than have the design say too much," Thuftedal said.

• "Color on the front door is a great way to give a house a facelift," Frisk said.

• If multiple rooms are visible, particularly in a smaller house, using different colors in each room can look "too choppy," Bischoff said. She advises using a "light color that opens up a space and running that color through the space." For variety, "drop in an accent wall."

• Use black or almost-black to give weight and define shape, Frisk suggested. For example, a dark neutral or black turns the railing into "a neutral anchor in a space."