7.4. 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 Netscape 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 Netscape 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 Netscape
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 Netscape color palette, and applications
that do not use this palette. The applications that do not use the Netscape 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.
7.4.1. To Use Themes That Use the Netscape Color Palette
Some window frame themes use colors that are in the Netscape
color palette. Bright and Esco use colors from the Netscape color palette.
Bright and Esco do not have the grainy appearance of other themes 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 the theme, see To Use Themes Which Require Less CPU Resources.
7.4.2. 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 Netscape
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.
7.4.3. 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 applications.
For information on how to turn off the splash screen, see To Reduce CPU Usage by Turning Off the Splash Screen.
7.4.4. To Reduce Color Usage by Using a Solid Color for the Desktop 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 desktop 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 choose Applications->Desktop Preferences->Background, then choose a solid color for the desktop
background.
