Reducing Color Usage and Improving Display Quality

Many modern computer systems support 24-bit color, that is, 16,777,216 colors. However, many users still use systems that support 8-bit color, that is, 256 colors.

The GNOME Desktop uses the websafe color palette. This palette is a general-purpose palette of 216 colors, which is designed to optimize the use of color on systems that support 8-bit color. However, some visual components of the GNOME Desktop are designed for systems that support 24-bit color.

The following display problems might occur on systems that support 8-bit color:

• Windows, icons, and background images might appear grainy. Many themes, background images, and icons use colors that are not in the websafe color palette. The colors that are not in the palette are replaced with the nearest equivalent or a dithered approximation. This use of replacement colors causes the grainy appearance.

• Applications that do not use the websafe color palette have less colors available. Color errors might occur. Some colors might not appear in the user interface of the application. Some applications might crash if the application cannot allocate colors.

• Color flashing might occur when users switch between applications that use the websafe color palette, and applications that do not use this palette. The applications that do not use the websafe color palette might use a custom colormap. When the custom colormap is used, other visual components might lose colors, then become unviewable.

The following sections describe how to optimize the appearance of the GNOME Desktop for systems that support 8-bit color.

To Use Theme Options That Use the Websafe Color Palette

Some window frame theme options use colors that are in the websafe color palette. Bright and Esco use colors from the websafe color palette. Bright and Esco do not have the grainy appearance of other window frame options on 8-bit color displays. Use Bright or Esco for the best color display on 8-bit visual modes.

For information on how to change theme options, see To Use Theme Options Which Require Less CPU Resources.

To Reduce Color Usage by Turning Off Display of Icons in Menus

Some items in menus display an icon beside the item. If the icon contains colors that are not in the websafe color palette, this feature can increase the number of colors used.

For information on how to turn off this feature, see To Reduce CPU Usage by Turning Off Display of Icons in Menus.

To Reduce Color Usage by Turning Off the Splash Screen

You can turn off the splash screen to make more colors available for the GNOME Desktop and for applications.

For information on how to turn off the splash screen, see To Reduce CPU Usage by Turning Off the Splash Screen.

To Reduce Color Usage by Using a Solid Color for the Background

Use a solid color for the desktop background. Use of a solid color reduces the number of colors used by the GNOME Desktop.

To set a solid color for the background, run the following commands:

# gconftool-2 --type string --set /desktop/gnome/background/picture_options none

# gconftool-2 --type string --set /desktop/gnome/background/color_shading_type solid

# gconftool-2 --type string --set /desktop/gnome/background/primary_color \#hexadecimal-color

Alternatively, users can use the Background preference tool to choose a solid color for the background.