Professional decorator's go by the system of primary, secondary, and tertiary colors to design a room's interior color scheme. Though these terms may sound intimidating, they are really simple terms applied to how you use colors in a room for the best overall effect.
1 - Primary Color
Primary color is the base color of your room. It will be the largest amount of color you use. For instance, if you decide red is your primary color, you will have either red upholstery, red walls, or both. When you look into the room, your eye will be drawn to red first.
2 - Secondary Color
Secondary color is the complimentary color to the primary color. Look on the web for a color wheel, or pick one up at a paint store. Look across from your primary color, and this will be the secondary color. Using the example red being the primary color, the opposite color on the wheel is green. You would use this color for accents such as large decorative bowls, a side chair, or draperies. It will be the second most noticed color in your theme.
3 - Tertiary Color
Tertiary color will be on either side of the secondary color on a color wheel. If green is your secondary color, then you can choose from yellow-green or blue-green. Use one or both in toss pillows, and other small accessories to complete a designer color scheme in your room.