Color and Contrast

Poor choice of colors on the screen can cause problems for users with color blindness (for whom hue is important) or low-vision (for whom brightness/contrast is important). Generally, you should allow the user to customize the colors in any part of your application that conveys important information.

Users with visual impairments may require a high level of contrast between the background and text colors. Often a black background and white text is used to prevent the background from "bleeding" over. These settings are critical for users with visual impairments.

  • Don't hard-code application colors. Some users need to use particular combinations of colors and levels of contrast to be able to read the screen comfortably. Therefore all the main colors you use in your GNOME application should be taken from the GTK theme, so the user can set the colors for all their applications to something legible just by changing the theme. If for some reason you do need to use colors that are not available in the theme, ensure they are customizable within the application itself.
  • Don't use color as the only means to distinguish items of information. All such information should be provided by at least one other method, such as shape, position or textual description. See Color and Contrast Examples.
  • Support all the high contrast GNOME themes. Ensure that when one of these themes is selected, all the text in your application appears in the high contrast foreground and background colors specified by the theme.
  • Ensure your application is not dependent on a particular high-contrast theme. Test it with different high-contrast themes to ensure your application respects the settings.