Home » Tip of The Day » Invert Pixels, Selections, and Masks.Invert Pixels, Selections, and Masks. December 12, 2016. Posted in: Tip Of The Day. To invert colors (i.e. white to black, or red to cyan) press Ctrl I (Mac: Command I) on your keyboard. This works in layers, selections, and layer masks. « Previous Photoshop Tip: | Next Photoshop Tip: » Sign-up for the PTC Newsletter so that you'll never miss a tutorial!. Your Email Address: