BodyShop Business
Color Matching Made Easy
Mark Clark
6/1/1997

When the vehicle manufacturers can hold a color standard, color match will be much easier; until that time, painters will have to tint and blend many vehicles to achieve an invisible repair - the ultimate goal of any production painter.

I've been around long enough to remember many heated discussions about the desirability of blending a mismatch onto adjacent panels. "If the edge of the repainted panel doesn't exactly match the edge of its neighboring ones, the customer is being cheated," said one side.

Unfortunately, chasing that elusive, dead-on color match took too much time - much more time than was allowed on the repair order. I've always believed that the best repair is the one done correctly in the least amount of time and kept invisible to the customer. With the following matching method, those are the kind of color matches you'll be able to do.

Test Panels

Any productive discussion about color match begins with the dreaded test panel. Painting the vehicle with an untested color - and then unmasking to find the color isn't right - wastes valuable time and expensive materials. Unfortunately, most painters do exactly that before they consider using a test panel.

A test panel - often a treated paper card, half black and half white - is used to determine when the color applied to the two-tone panel is shot to full hiding. When the paint covers the test panel completely, you can't see the difference between the black and white halves. In these days of translucent base colors, this may create a problem if the painter keeps shooting until the black and white card is uniformly colored. If the color in your gun doesn't want to hide very well, chances are the color at the car plant didn't hide well either. One possible solution to prevent the overhidden color is to seal the test panel with the same color undercoat the auto factory used. Two or three coats of a poor hiding color over the same colored sealer the car factory used may provide the best chance of a match.

Productive Paint Matching

Making money in the paint shop means keeping the painter productively occupied while the current coat of primer/paint/clear is drying. However, there are operations that shouldn't be performed during these intervals. Machine sanding the next car in line will get the painter covered with dust; polishing the last car painted with a pad and compound will contaminate the painter's clothes also. One of the best ways to productively spend the down time between coats is to do something about the color on an upcoming job.

That something starts with looking up the complete paint-code number on the vehicle. Car manufacturers really do want you to be able to repaint their damaged automobiles quickly and correctly, so use all the information provided on the paint-code tag to locate the formula the car and paint manufacturers think will match. This "prime" or "standard" color formula will match the majority of vehicles painted with that particular code. However, the car in your shop may not have been painted with that exact color. The paint companies watch for a measurable drift away from a color standard for any given automobile color. When they can identify enough cars painted with the "off-standard" color, they develop an alternate formula to match just those cars.

With the possibility of an off-standard color in your shop, diligent ground work by the painter includes examining all color offerings for that paint code. Sometimes, the off-standard offering is displayed on a chip; other times the color is described - but hearing a color described as "darker flop and redder face" may be less than you, as a painter, want.

Mixing the Match

The best way to proceed is to mix up a small amount of the suspect color and shoot a test panel. Mixing small amounts is a snap on a computerized mixing scale - all you need to do is specify the number of ounces you want. Another way to mix small amounts of color quickly is to simply slide the decimal point one place to the left. For example, one quart is 32 ounces, so by moving the decimal point one place to the left, you can mix 3.2 ounces of color.

Once the test quantity of color is mixed, make sure to spend enough time stirring or shaking the paint to ensure thorough mixing of the tints. Reduce the small amount of color with the same reducer you'll use to paint the car, and then spray a test panel with the same spray gun at the same air pressure you'll use when painting the actual surface. In an effort to speed this process, I recommend the painter force dry the test panel with a heat light or heat gun between coats.

As soon as possible, clear the test panel (when the original finish is base/clear) with any clear. Using the same high-solids, isocyanate-catalyzed clear that will be applied to the vehicle is not necessary on the test panel. An aerosol can of clear lacquer or clear enamel will work fine to determine a blendable color match. Not clearing the panel at all and trying to wet the basecoat with water or wax and grease remover to simulate a clearcoat is a bad plan. Any "clear" that flashes off the test panel won't provide an accurate picture when comparing the panel and the car. Aerosol clear will work fine as long as the clear in the spray can is as yellow or as clear as the real clearcoat.

Let's say that the first off-standard color didn't look good enough to try a test panel. Your next step: try another alternate formula. Try mixing 3.2 ounces of the new color (let's say it looks more like the car) and apply the color to a test panel, drying between coats with a heat gun. Clear with an aerosol clear and compare the test color to the car. Still not close enough to blend? Now it's time to tint the color to get closer to that of the car. Remember, though, the object is to find a color that can be blended onto the adjacent panels, not to butt match the car.

Color Theory

There are three dimensions to color theory. The color wheel isn't a wheel at all but rather a globe or a ball. Part of the confusion surrounding color tinting is that the three dimensions - out the center spoke, around the outside edge, and down the north and south pole - each have several names to describe the same parameter.

For example, the measurement around the outside is correctly called cast, hue or color. The down axis is called light/dark, value or lumination. And the out-spoke on a color wheel is correctly called richness, strength, saturation, intensity or chroma (no wonder people are confused).

My method doesn't use any of these terms. Here's how it works:

There are only three primary colors - red, yellow and blue. Draw a circle and place one of the three primary colors on the color wheel. Place the remaining two colors at equal distances around the circle, in any sequence. Now, plug in the secondary colors, which are the three colors made by blending two of the three primary colors in equal parts. Most folks can tell you what color results when mixing blue and yellow - green. Fewer people can name the color made by mixing yellow and red - orange to us industry insiders. The color resulting from a combination of red and blue is the toughest for most folks to name. Depending on where and when you went to grade school, that color is either violet or purple.

Now, with the six colors marked on the circle that represents the "around dimension" of color theory, it's possible to start tinting.

The most difficult component of color matching is the out-spoke. The problem is that a color wheel is really three dimensional, not flat. Matching a color isn't as simple as moving three steps from the center of the wheel toward the edge. The color could be three steps out, two steps left and two steps up (this is why color-tinting school lasts three days).

The "down dimension" is the easiest to correct. Anyone walking by your paint shop can tell if a color is lighter or darker than another color. To make my abbreviated color-tinting system work, we'll ignore the down dimension for now (that was easy enough), and we'll endeavor to move the color around the wheel's edge first and fix the down (light/dark) problem last.

Methodology

The notion with my method is that a color can only be off toward its direct neighbors - the color one place left or right on the color wheel. For example, if you had a red car, your color could be off by being too orange or too violet, period. It won't be off by having too much yellow, green or blue - those aren't neighboring colors. Likewise, if you had a blue car, the color could be off by having too much violet or too much green - blue's neighboring colors.

Sometimes, the problem is determining which way to move, left or right. The solution is pretty simple. Take two identical drops of the color you've mixed up. To one drop, add a small amount of the "left" tinting color, and to the other, add a dab of the "right" tinting color. For example, if the car you're working on is green, take two drops of the green color directly from the can. To one drop, add a little of the yellow mixing color found in the formula. To the other green drop, add some of the blue mixing tint found in the formula.

Rather than producing the perfect color, this test will instead identify the tint that's obviously wrong. For example, when you stir the yellow tint color into the green drop, it will make a new color. Likewise, the green drop stirred with the blue tint color will make a new color. One of these new colors will look nothing like the color you're trying to match, so now you know it's the other tint color that needs to be added to your green color to match the car.

At this point, a light goes on in the heads of painters who have been horribly confused about color tinting. "Hey," they say, "that's easy."

The hard part comes in determining how much of that tinting color - once chosen - should be added. Color tinting is a time-consuming process. This simple method will get you off in the right direction, but the actual tinting task is still difficult and tedious. Tint small amounts of color at one time and measure the amount of tint you're adding on a scale.

After moving your color in the right tinting direction, you may still need to lighten or darken the color. One choice is to move the color around the wheel first, then do the light/dark adjustment. Sometimes, it's beneficial to alternate "hits" to the color between the left (or right) tint and the tint that will lighten/darken the color. Use aluminum or pearl to lighten reflecting colors; use white to lighten solid colors. Avoid using black to darken colors that don't contain black in the formula. Instead, try using the darkest shade of the major tint in the formula. Shoot test panels when you think the tinted color is close enough to blend.

Note: The matching method described won't be much help when your color-match problem is white, silver or brown. White and silver aren't found on the color wheel, and the entire center of the wheel is brown.

Applying Theory to Practice

The good news is that this simple system of three primary colors drawn on a circle will lead you to a blendable color match - most of the time.

As you recall, we skipped the most difficult part of color tinting, the "out" dimension. As a result, the method I've just described will only produce a blendable color about 80 percent of the time. The other one in five cars will need to address the third color dimension - the out-spoke - to achieve a blendable match.

No matter what color car you're painting or how many color-wheel dimensions you must explore to get a color match, remember that blending is the goal - not butt matching. Don't make your job any harder. Once a color is close enough to blend, stop tinting. It's as easy as that.

Mark Clark, owner of Clark Supply Corporation in Waterloo, Iowa, is a contributing editor to BodyShop Business.

Check It Out

Chasing that elusive, dead-on color match can take a lot of time - much more time than is allowed on a repair order. To get the best blendable match in the least amount of time, remember the following color-matching points.

  • A test panel is often a treated paper card, half black and half white. It's used to determine when the color applied to the two-tone panel is shot to full hiding.
  • Start your color-matching process by looking up the complete paint-code number on the vehicle. This "prime" or "standard" color formula is the one the car and paint manufacturers think will match the majority of vehicles.
  • When paint companies can identify enough cars painted with an "off-standard" color, they develop an alternate formula to match those cars. Sometimes, the off-standard offering is displayed on a chip or is described.
  • Mix up a small amount of the suspect color and shoot a test panel. If you don't have a computerized mixing scale, mix small amounts of color by sliding the decimal point one place to the left.
  • If your first color doesn't look good enough to try a test panel, try an alternate formula. If it's still not close enough to blend, tint the color. Remember, the object is to find a color that can be blended onto the adjacent panels, not to butt match the car.
  • To begin tinting, draw a circle and place the three primary colors - red, yellow and blue - at equal distances on it. Between those colors, place their secondary colors - green, orange and purple. These six colors marked on the circle represent the "around dimension" of color theory.
  • With my method, a color can only be off toward its direct neighbors - the color one place left or right on the color wheel. For example, if you had a red car, your color could be off by being too orange or too violet, period.
  • To determine which way to move, left or right, take two identical drops of the color you've mixed up. To one drop, add a little of one of the tinting colors; to the other drop, add a little of the other tinting color. This will identify the improper tinting color.
  • Avoid using black to darken colors that don't contain black in the formula. Instead, try using the darkest shade of the major tint in the formula.
  • This simple method will get you off in the right direction, but the actual tinting task is still difficult and tedious. Tint small amounts of color at one time and measure the amount of tint you're adding on a scale.



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