Selective Color

Another very useful tool for applying specific color adjustments to print images is Selective Color. The Selective Color feature mimics the color controls found in most prepress drum scanners, which allow you to adjust “color in color.” The Selective Color Options dialog box contains four sliders, one for each color in the CMYK color space (Cyan, Magenta, Yellow, and Black). This makes it an ideal tool for tweaking images that have already been converted to CMYK. You can choose a general color to adjust in the image from the Colors menu at the top of the dialog, and then move the CMYK sliders to the left or right to shift them toward a primary color.

Moving a slider to the right shifts whatever color is selected from the menu toward the color that the slider controls (cyan, magenta, yellow, or black). Moving a slider to the left shifts the chosen color toward the exact opposite color on the color wheel from C,  M, Y, or K. Therefore, even though the dialog uses CMYK sliders, you can add red, green, and blue by moving the Cyan, Magenta, and Yellow sliders to the left (something to keep in mind when using Selective Color with RGB images). The bottom of the dialog box offers two ways to adjust selective color: the Relative or Absolute method. The Relative method changes areas relative to how they started, whereas the Absolute method applies the exact amount specified. In general, Relative mode is a much gentler adjustment, which makes it more useful than Absolute mode for fine-tuning color in CMYK images.

Selective Color can be used as an alternative to Curves for balancing the magenta-to-yellow ratio in CMYK images containing lighter flesh tones. Like Curves and Levels, Selective Color is also available as an adjustment layer, which means that you can store your settings in a layered CMYK TIFF or PSD file and change them later as needed—even after the image is placed in a layout. Notice that in addition to the RGB and CMYK colors, the Colors menu also contains options for adjusting Whites, Neutrals, and Blacks. By choosing Blacks from the Colors menu and moving the Black slider to the left, you can lighten the shadow areas of an image. If you’re preparing a CMYK image that contains a lot of black areas for press, you can make the blacks richer by moving the sliders to the right and applying the preferred “black build”.

You can brighten the highlights in an image by choosing Whites from the Colors menu and moving the Cyan, Magenta, and Yellow sliders to the left. This is especially useful when working with metallic images, in which case you may want to try using Absolute mode to heighten the effect. With Neutrals chosen from the Colors menu, you can adjust the midtone areas of an image. By moving the Black slider to the left, you can lighten the midtones and help bring out detail. Keep in mind that unless you make a selection first, all neutral Selective Color adjustments are applied to the entire image. This is why Curves is still the better tool for fine-tuning specific areas of an image.