Removing Color Casts

Images that have the pure color tones black, white, or neutral gray are easy to correct. In each case, simply click the corresponding eyedropper for color correction. The real world is different, however, since you rarely shoot color charts in a laboratory. Therefore, you really need to consider applying Photoshop’s color correction tools. To name them all would go beyond the scope of this chapter. In the appendix, there is a list of recommended Photoshop guidebooks that describe these techniques in detail.

Identifying Color Casts

Before a color cast can be corrected, it first must be identified. The Info tab (second tab in the Navigation toolbox) can be immensely helpful. In the photo, the cursor is on a white mussel. According to the RGB principle, the three color channels should have roughly identical values for pure white. This is not the case with the picture of the mussels; it obviously has a color cast.