Today’s open-plan designs for homes, where living rooms, dining rooms and kitchens may be one big space, color becomes a prime way to define spaces and create the focal points that are essential for successful home decorating. Of course the key to using color is deciding which colors and how to use them.

Many designers recommend using color to pay up a room’s architectural features. Arched doorways, mantels, molding, built-in bookcases, wainscot, windows and doors are all opportunities to define a living area using color.

For example, painting doorways or molding a shade that’s one step darker or light than the primary wall color can add subtle emphasis. Although it’s only one tone away from the primary color, it draws the eye to that detail.

Using two different colors in the same room gives a bolder approach. One example would be to paint a wall niche or a built-in bookcase a shade of green that’s compatible with blue walls. The different color serves to highlight the books or artwork in the recessed area.

Painting all architectural elements the same color is a longstanding technique for providing continuity. An example would be the use of white or off-white for doors, windows and molding, a technique used since America’s Federal period in architecture. Conversely, a room with wainscot (also known as a chair rail) serves as an opportunity to highlight the contrast between dark and light. A bright white wainscot against a colored wall will draw attention to itself, while a dark wainscot against a bright wall will draw the eye toward the upper walls.

Paint also serves to give the illusion of a wainscot where there isn’t one. To achieve this effect, paint the lower third of a wall one color, and then paint the top two-thirds in a different color. Where the two colors meet on the wall, install a piece of flat molding painted in the lower color. Voila! Instant faux wainscot!

Rooms that lack distinctive architectural features can be the most difficult to liven up. Here’s where the technique of painting an “accent wall” comes in handy. To use this technique, designers suggest painting primary walls a soft white or a neutral shade such as beige or celadon green. Then create the accent wall using a paint that’s three shades deeper than the primary walls. This gives the room emphasis without being overwhelming.

Even when inspired by these painting techniques, there remains the dilemma of what color to choose. Color consultants suggest that home decorators start by remembering that even though your favorite home improvement store may have thousands of paint color samples, there are only seven colors in the spectrum of light and paint. These colors are the same as the ones you see in a rainbow; in order, red, orange, yellow, green, blue, indigo, and violet (often remembered by the mnemonic, “Roy G. Biv”).

Unless your home is getting an extreme makeover, a good place to begin is to choose three colors from something that’s already in the home. A pillow from the sofa, a favorite outfit, or an artwork – whatever sparks an emotional reaction. Take those objects to the store and find three samples that match those colors. This gives a range of 15 to 18 shades to use, since each paint sample typically has five to six colors.

Choose one of these as the primary wall color by looking at the darkest shade at the bottom of the sample. If the darkest shade appeals to you, there’s no doubt you’ll like the lighter versions as well. Then your other favorite colors can be accents, and before you know it, you have a home decorated in color schemes that both beautify and define your living spaces.