Matching paint and carpet colors requires patience and a bit of perseverance. The problem begins with the paint chip. It only provides you with a minimal view of the color, which changes once it's on the wall. The reason for this effect is metamerism -- it happens when you put on two seemingly alike dark-colored socks in the morning under one type of light, only to discover that you have one blue and one black sock on when seen in the light of day. Take the time to match paint color choices to your carpet under all types of lighting so you'll be pleased with the final results.
Natural Light Effects
The amount of natural light in a room affects color perception and causes subtle changes to wall and carpet colors as the sun moves during the daylight hours. Light also intensifies or lessens based on which direction the windows face in the room in relationship to the sun's arc across the sky. Rooms with north-facing windows receive a hint of blue light, accentuating a blue carpet and pale blue walls, while west-facing rooms receive the warm oranges produced by the sunset glow, which can saturate yellows, oranges and reds in the carpet and on the walls. Rooms that face east get a dose of green, making these colors appear more vibrant, while south-facing rooms receive the most intense, bright light of them all, which shows up marked differences between shades, tints or tones.
Testing Color Choices
Bring a sample of the carpet with you when you begin the selection of paint chips and colors to narrow down your choices immediately. Compare them inside the store's bright lights and in the direct light outside for a truer match. After selecting multiple paint chips in varying shades, tones or tints of your color -- celadon green for walls for a sea-foam green carpet, for example -- bring them home and hang them on the wall in the room where you plan to add them. But first, hold them against the carpet sample for a comparison inside the home. Periodically check the paint chips at various times of the day in the room to notice the changes. Narrow your selection down to one or two colors.
Pick up two or more small paint samples. The minor cost is nothing compared to having to paint your room twice to get its color matched to your carpet. Select an area of the wall exposed to the natural light in the room. Paint a 1-by-2-foot area, next to the carpet -- don't forget to tape it off to prevent drips -- with the colors separated by a few inches, but basically side by side. Live with these colors on the wall for a few days or weeks – however long it takes -- to find the one that works the best for the carpet. You can watch how the light changes the paint's color directly and avoid costly redos.
Once daylight has faded, examine your paint samples again under different types of lights. Incandescent, compact fluorescent and LED bulbs all have a different effect on the colors on the wall. Incandescent lights add warmth, while fluorescent light drains certain hues of their color, making a beige on the wall appear green against a beige carpet. When you compare the paint samples on the wall in daylight and electric light, it allows you to settle on the color best matched to your carpet. But don't pick a color based on a bulb you don't plan on using in the room. Choose the color that works best in all lighting options, and then you can enjoy its results for years to come, no matter what the light does in the room.
Metameric Color Effects
Metamerism doesn't affect all colors, but for most carpet colors, it comes into play. Colors most likely to change based on different lighting sources include colors in the beige, tan or taupe neutral family; grays and gray-blues; tints and shades of mauve, lilac or light purple; and celadon, a muted celery-green. Matching a red, dark green or blue carpet is not as hard to do, as these colors aren't as easily affected by metameric changes.