Match color under the right light
Next time you're in the paint aisle of a store, study how paint chip displays are lit. Chances are the paint manufacturer included special lights on its displays, and for good reason: Light sources can play tricks with how you perceive color. Different light sources also can throw off your ability to match dyed or stained wood.
The red, orange, yellow, green, blue, indigo, and violet that make up sunlight, as shown in the chart below left, are reproduced, to an extent, by artificial lights. The amount and strength of each color varies by the type of light. For example, cool white tubes in fluorescent fixtures -- a common choice for workshops -- cast a cool, greenish-blue light that downplays the red portion of the light spectrum, as you can see in the chart below middle. Standard incandescent lights, shown in the chart below right, emphasize yellow and red, but not green and blue.
To match the finish on a project to another piece of furniture or a sample, first match your light spectrums. For example, the lack of red in fluorescent lights saps the red color from a warm mahogany-stained finish while the warm color of incandescent lights may exaggerate the red tones.
Problems start when you try to match colors under a light source that will change once the project leaves your shop. "You don't have any red in fluorescent lighting, so you tend to stain things much too red under fluorescent light," cautions Alan Noel, an Atlanta furniture finisher. "The rule that's always worked for me is to match things under natural light. If it matches outside, it matches anywhere."
Noel matches colors at his indoor spray booth, which is fitted with halogen lights. Of all the incandescent light sources, halogen is closest to the natural light spectrum.
- Make sample pieces using the same brand and shade of stain or dye (from the same can is ideal) you'll use on the project, and finish them with the same topcoat to avoid gloss or color differences. Using different wood coloring products for the sample and the project could leave you vulnerable to a problem called metamerism. That's when two objects appear the same color under one light but different colors under another type of light.
- Purchase or mix enough wood coloring products to complete your current project and any additional projects you expect to build later as part of the same collection. This is especially important when you mix wood dyes in your workshop. Fortunately, mixed dyes can last for years.
- If you can't place a sample under the light source where the finished project will be located, reproduce the lighting in your shop.
- Upgrade your shop lights. Replace bargain-priced cool white tubes with warm white tubes that produce a broader spectrum of light.
- Even the color of sunlight varies with the time of day. Morning light has a cooler, bluish cast while afternoon sun has more warm yellows. For the best balance, use midday or early afternoon sun as your color benchmark.