Professional photographers rely on color charts to ensure color accuracy in even the most difficult lighting situations. Color charts not only provide for a more accurate white balance but they also help when it comes to fine-tuning other colors in a scene—from skin tones to flowers, foliage and more.
And color charts aren’t a digital-specific invention. For many decades professional photographers, videographers, printers and designers have used color cards to ensure color accuracy. The advent of digital capture, however, has spread the practice of using color charts far and wide and into the hobbyist realm as well.
Putting a color chart to use is simple. Have the subject hold the chart in the scene, under the same illumination to be used for the finished photograph. The chart can also be propped in place or held by an assistant, so long as it’s not angled in such a way to create obscuring shadows or reflections on its surface. Then, just take a picture and evaluate the results. You can, of course, use the neutral gray tones on the card to help dial in a precise white balance in post, but you can also evaluate the particulars of the other colors on the chart. If the pink is too blue, for instance, or the green is shifting to yellow, know that your white balance or gelled lights are in need of adjustment.
Many modern color charts come with software that works in conjunction with the card. This allows you to photograph the chart, import the picture into a computer and then create a color profile customized to the shoot. Even if your color card doesn’t come with software, or if you’re using a vintage color chart, you can always download Adobe’s free DNG Profile Editor to create a custom camera profile from a photographed color chart. Simply photograph the color chart, import the image as a DNG file (which can be created on import via Adobe’s Lightroom application) and then open that file in the DNG Profile Editor. It will then walk you through the process of clicking on four colors of the chart to create a custom camera profile.
Most color charts have 24 squares of color. But they’re not just a random variety of tones. In fact, each one was deliberately chosen for its role in representing popular colors in people, in nature, and even in the four-color printing process.
The classic color chart design has been around for nearly 50 years, originally called the Macbeth ColorChecker. Today, many manufacturers produce their own versions of the cards, typically relying on the same 24 squares representing the same 24 tones—albeit sometimes in slightly different positions. Here’s a rundown of the colors on the chart and what they represent.
Skin Tones: Light and Dark Brown – While humans come in a wide variety of colors, the color chart only includes two—light brown and dark brown skin tones. While that’s not nearly enough to encompass all the possibilities, it does serve as a baseline range for monitoring the reproduction of different skin tones.
Nature: Sky Blue, Green Foliage, Blue Flower and Bluish Green – These color squares are meant to aid in color matching with naturally occurring—and therefore very widespread—natural elements.
Secondary Colors: Orange, Purplish Blue, Moderate Red, Purple, Yellow Green and Orange Yellow – Gardeners will tell you that these vibrant colors can be found in the flowers of many different plants, and portraitists and interior photographers know that these tones are also found in clothing and décor.
RGB and CMY: Red, Green, Blue, Cyan, Magenta and Yellow – This row of colors is deliberately aimed at aiding printers whose four-color printing process includes CMYK—cyan, magenta, yellow and black—as well as the three primary colors of light that photographers rely on for everything—red, green and blue.
Grayscale: White, Black and Four Neutral Grays in between – This row of neutral gray tones not only proves useful for dialing in color balance but also for determining exposure. If the black square looks gray, for instance, the image is overexposed.