In Photoshop, you can invert colors by using the Inverse Color command. To do this, press the I key and then select the color you want to inverted. To inverted the color, use the following steps:

  1. Choose a color from your palette and press the I key.
  2. Type a new value for the alpha channel of that color in the Alpha Channel field of the Inverse Color dialog box. The new value should be set to 1 (the default).
  3. Click OK to close the Inverse Color dialog box.