You can make a textual region colored simply by adding the keyword colored to the textual region definition.

The color specifications in the definition are for the background and foreground of the entire region, exactly like an uncolored textual region. The color specifications for individual characters in the region override the color specifications in the definition. Character locations that do not contain any text are displayed in the background color specified in the definition of the colored textual region.

Caution:        Do not use Color 26 or Color 27 when specifying foreground or background colors in a colored textual region. These colors will not work as desired.