Memory-Color Makeovers

In addition to using neutral grays to affect your color makeovers, the other key category of color correction values involves what are known as memory colors. Memory colors are certain kinds of colors that your human memory "just knows" are right or wrong — intuitively — by glancing at them. The colors we associate with (for example) blue skies, green grass, red stop signs, and skin tones are common memory colors. When such colors seem "off" in an image — even just slightly off — you tend to notice it right away. (For you portraitists out there, note that skin tones are especially important when the focus of the image is someone's face.)

Here you can see some examples of memory colors where you can tell right off that they are not quite right. You don't need an info tool to tell you that these color are wrong!

Unlike a neutral gray (where a specific numeric value, such as a 5% highlight, is the goal), skin tones require you to focus on ratios of red to green to blue (rather than specific numeric values). No matter if you're viewing a skin tone in the highlight, mid-tone, or shadow zone, the ratio of the RGB values should remain the same — even when the specific numbers vary.

Now, whole books have been written about skin tones, but I have a simple ratio you can use to make sure that people in your images look like humans and not Klingons. The RGB ratio I use most often when measuring and adjusting skin tones is R>G>B in a ratio of 5/4/3.

Here is how this works mathematically: If your skin tone Red value is 100, your Green value should be approximately 80 and your Blue should be approximately 60. To determine your Green and Blue values, do some quick arithmetic:

Multiply 20 x 4 to determine your target Green value: 20 x 4 = 80.

Multiply 20 x 3 to determine your target Blue value: 20 x 3 = 60.

To see how this ratio works in the "real world," make your way through the following steps:

1 Open the image entitled Taz_Portrait_RGB_300.

Here you'll use a portrait of the Taz with some serious color problems. (Taz Portrait_ RGB_300 is available for download from the Web site associated with this book.)

2 Choose ImageoDuplicate to make a duplicate copy.

As bad as the original may be, always work on a copy.

3 Choose WindowoInfo.

The Info palette makes an appearance.

4 Click the Eyedropper icon on the left side of the Info palette and select RGB from its contextual menu.

You'll be working with RGB values again.

5 Choose the Eyedropper tool from the toolbox and set its sample size to 3 by 3 Average in the Eyedropper tool's Options bar.

As before, you'll want to work with an average matrix size of 3x3 pixels.

6 Move your Eyedropper cursor over the sunlit (image-left) side of the forehead.

The RGB values measured here are R=203, G=177, B=172.

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