Setting a Color Reference Point

Place the Color Picker tool over a neutral gray area in the image. In this case I chose a rock on the shoreline. Set the Color Checker Point by holding down the Shift key while clicking with the mouse. The RGB values (116,142,172) are displayed in the Info pallete under #1. The idea is to increase the red value from 116 to 142 and decrease the blue value from 172 to 142 to make the rock neutral in color (142, 142, 142).