Selecting a color table option

Both the GIF and PNG-8 formats allow you to determine the color table for the image in the Settings panel of the Save For Web dialog box. This color table appears in the Color Table panel when that image is selected, and you can make changes to these colors. The color table for an 8-bit image has a maximum of 256 colors.

Perceptual Creates a custom color table by giving priority to colors for which the human eye has greater sensitivity.

Selective Creates a color table similar to the Perceptual color table, but favoring broad areas of color and the preservation of Web colors. This color table usually produces images with the greatest color integrity. Selective is the default option.

Adaptive Creates a custom color table by sampling colors from the spectrum appearing most commonly in the image. For example, an image with only the colors green and blue produces a color table made primarily of greens and blues. Most images concentrate colors in particular areas of the spectrum.

Web Uses the standard 216-color color table common to the Windows and Mac OS 8-bit (256-color) palettes. This option ensures that no browser dither is applied to colors when the image is displayed using 8-bit color. (This palette is also called the Web-safe palette.)

Using the Web palette can create larger files, and is recommended only when avoiding browser dither is a high priority. See Previewing and controlling dithering in Photoshop images.

Custom Preserves the current perceptual, selective, or adaptive color table as a fixed palette that does not update with changes to the image.

Mac OS Uses the Mac OS system's default 8-bit (256-color) color table, which is based on a uniform sampling of RGB colors.

Windows Uses the Windows system's default 8-bit (256-color) color table, which is based on a uniform sampling of RGB colors.

Other color tables appear in the menu if you have saved them previously. See Loading and saving color tables.

Images and Page Design > Choosing options in the Save For Web dialog box > Selecting a color table option