In calligraphy and typography, the use of handwriting or type of a different colour on a page, derived from the practice of setting off liturgical directions, headings of statutes, and the like in red. Specifically, it applied to the rules prescribed for the conduct of religious services as set forth in breviaries, prayer books, and missals. Though red is the traditional colour for rubrication (from Latin, rubricare : "to colour red"), the term is now extended to include inks of other colours either applied by hand or printed.
Detail showing the use of rubrication from the Gellone Sacramentary, 8th century (Paris, ...
By courtesy of the Bibliotheque Nationale, Paris