The Color Table command lets you make changes to the color table of an indexed-color image. These customization features are particularly useful with pseudocolor images—images displaying variations in gray levels with color rather than shades of gray, often used in scientific and medical applications. However, customizing the color table can also produce special effects with indexed-color images that have a limited number of colors.
To shift colors simply in a pseudocolor image, choose Image > Adjustments, and use the color adjustment commands in the submenu.
You can edit colors in the color table to produce special effects, or assign transparency in the image to a single color in the table.
You use the Save and Load buttons in the Color Table dialog box to save your indexed color tables for use with other Adobe Photoshop images. After you load a color table into an image, the colors in the image change to reflect the color positions they reference in the new color table.
You can also load saved color tables into the Swatches panel.