1. Open the image (a.jpg).
2. Open the Levels function (Cmd-L)[CTRL+L]. See Figure 1.
3. Switch to the Red channel by using either the popup menu or key commands (Cmd-1)[CTRL+1].
4. Using the sliders, crop the histogram. See Figure 2.
5. Repeat step 5 for the Green (Cmd-2)[CTRL+2] and Blue (Cmd-3)[CTRL+3] channels. See Figure 3 and Figure 4.
6. Return to the composite RGB Levels, and observe the effect of the changes by looking at the image and make midtone adjustments accordingly. See Figure 5.
7. Close the Levels by clicking the [ok] button. Accepting the changes will redistribute RGB color information. The result will increase contrast and will tend to balance image color.
[NOTE: your monitor must be calibrated for the following steps.]
8. Open Color Balance (Cmd-B)[CTRL+B].
9. Swing the top slider (Cyan Red) to the right and left of center while watching the image. If the change to either side creates something visually pleasing, swing the slider through the full range on that side (-100 to 0, or 0 to +100), and decide the best position based on what you see on screen.
10. Repeat Step 9 for the middle (Magenta Green) and bottom (Yellow Blue) sliders.
11. Repeat Step 8 and 9 to help rebalance the color. Because each slider is adjusted separately, adjusting again can better optimize how the sliders affect one another. These second changes may be minimal.
12. Click the Highlight button (in the Tone Balance panel) and repeat Steps 9 thru 11.
13. Click the Shadow button (in the Tone Balance panel) and repeat Steps 9 thru 11.
14. Close the Color Balance by clicking the [ok] button. This will apply the changes.
15. Compare the before and after changes for the original state (Open), the Levels correction (Levels) and Color Balance adjustment (Color Balance) by clicking on the appropriate states on the History palette.