There will be times when you want to add color that wasn't originally part of your image, and Photoshop gives you lots of ways to do that. The techniques in this section will serve you well if you're colorizing a black-and-white image, and if you're painting on an existing color image or an empty canvas.
If you want to add a quick color tint to a black-and-white image, use the Variations command. It's not available as an Adjustment layer, so, to be safe, duplicate your image layer first by pressing ⌘-J (Ctrl+J on a PC).
The Variations adjustment only works when you launch Photoshop in 32-bit mode. Flip back to the box on What Does "64-bit" Mean? to learn how!
Choose Image→Adjustments→Variations, and in the center of the honkin' big dialog box that appears (Figure 8-22), you see a slew of previews surrounding your original image. Each preview has one of the six basic colors added to it: green, yellow, red, magenta, blue, and cyan. To add a blue tint to your image, for example, click the More Blue preview and Photoshop applies its effect to your current pick in the center of the dialog box. If you want to add even more blue, click the blue preview again (the clicks are cumulative). Over on the right side of the dialog box, you can click the Lighter or Darker preview to lighten or darken your current pick (these clicks are cumulative too, so if you want the tint to be even lighter or darker, keep clicking away).
Figure 8-21. An Invert Adjustment layer turns ...