As part of the optimization process, you can have one or more colors in an animated GIF be displayed as transparent in a web browser. This is useful when you want a web page background color or image to show through the animation.

To display a color as transparent in a web browser:

  1. Select Window > Optimize if the Optimize panel is not visible.
  2. From the Transparency pop-up menu in the Optimize panel, select either Index Transparency or Alpha Transparency. For a description of these options, see Making areas transparent.
  3. Use the transparency tools in the Optimize panel to select colors for transparency.

    This is a picture of the feature being described.