Installing Icons for Themes
The GNOME Desktop provides several themes that are designed
for users with special visual needs. For example, some of the themes are designed
for users with low vision. Several versions of icons might be required so
that the icon can be displayed properly in each theme.
You might need to install a new icon for an application. When you install
a new icon, you must create several versions of the icon, so that the icon
displays correctly in the themes. You must create several versions of the
following types of icon:
Icons that are used within applications in the GNOME Desktop.
Icons that are used internally by GTK+ applications, or GTK+
stock icons.
When you install a new icon, you must create several versions of the
icon, so that the icon displays correctly in the themes. You can create the
icons in several formats, for example Portable Network Graphic (PNG) format.
The suggested size of icons for the desktop environment is 48 pixels by 48
pixels. At this size, most themes can rescale the icons.
When you install a new icon, create the following 48 pixel by 48 pixel
versions of the icon:
If possible, create 16 pixel by 16 pixel versions of the each of the
icons above also, for themes that do not require large print.
Install the icons to the image files location that is specified for
the theme in the section called “To Install a New Controls Option” or the section called “To Install a New Window Frame Option”. For example,
to add icons to the HighContrastLargePrint theme, add the icons to the /usr/share/themes/HighContrastLargePrint/pixmaps directory. Add
references to the icons to the relevant theme files. For example, to add icons
to the HighContrastLargePrint theme, add references to the icons to the /usr/share/themes/HighContrastLargePrint/gtk-2.0/gtkrc file. Modify
the gtkrc file for the theme to associate the icon with
a GTK stock icon identifier.
For more information on how to create icons for application launchers
and for panels, see https://www.freedesktop.org/Standards/icon-theme-spec.