38.13.3 XPM Images

To use XPM format, specify xpm as the image type. The additional image property :color-symbols is also meaningful with the xpm image type:

:color-symbols symbols

The value, symbols, should be an alist whose elements have the form (name . color). In each element, name is the name of a color as it appears in the image file, and color specifies the actual color to use for displaying that name.