Using Levels to adjust color (Photoshop)

In addition to setting the tonal range, you can use Levels to adjust the color balance of an image.

To use Levels to adjust color balance:

1. Place a color sampler on an area of neutral gray in the image.
2. Do one of the following to open the Levels dialog box:
• Choose Image > Adjustments > Levels.
• (Photoshop) Choose Layer > New Adjustment Layer > Levels. Click OK in the New Layer dialog box.
3. Do one of the following to neutralize a color cast:
• Double-click the Set Gray Point Eyedropper tool  in the Levels dialog box to display the Adobe Color Picker. Enter the values you want to assign to the neutral gray, and click OK. Then click the color sampler in the image. For more information on using an eyedropper tool, see Using the eyedropper tools to remove a color cast.
• Click Options in the Levels dialog box. Click the Midtones color swatch to display the Adobe Color Picker. Enter the values you want to assign to the neutral gray, and click OK. This method has the advantage of showing you a preview of the values you're assigning.

In general, assign equal color component values to achieve a neutral gray. For example, assign equal red, green, and blue values to produce a neutral gray in an RGB image.