Deleting colors from the color table

You can delete selected colors from the color table to decrease the image file size. When you delete a color, areas of the optimized image that previously included that color are rerendered using the closest color remaining in the palette.

When you delete a color, the color palette type is automatically changed to Custom. This is because the Adaptive, Perceptual, and Selective palettes would automatically add the deleted color back into the palette when you reoptimize the image. (The Custom palette does not change when you reoptimize the image.)

To delete selected colors:

1 With a GIF or PNG-8 image displayed, select one or more colors from the Color Table panel, as described in Selecting colors.

2 Delete the color:

Deleting a color changes the color palette type to Custom to prevent the color from being added back to the palette if you reoptimize the image. To return to an Adaptive, Perceptual, or Selective palette, select the palette from the color palette menu. (See Selecting a color table option.)

Images and Page Design > Working with the color table in Photoshop images > Deleting colors from the color table