There are a few ways to change the color of a wall in Photoshop. The first way is to use the color picker. To select a color, click on the color wheel at the bottom of the palette and then select a color from the list. The second way is to use the hue and saturation tools. To select a hue, click on one of the orange or yellow circles in the hue wheel and then select a saturation from the list. To select a saturation, click on one of the blue or green circles in the saturation wheel and then select a value from the list. The third way is to use an adjustment layer. To create an adjustment layer, click on New Adjustment Layer atthe bottom of your palette and then name it Wall Color. After you have created an adjustment layer, click on its icon to open its properties window. In this window, you can change many of its properties such as opacity, brightness, contrast, and other factors.