(The). The civil code of ancient Rome. Juvenal says, “Per lege rubras majoram leges” (Satires, xiv. 193). The civil laws, being written in vermillion, were called rubrica, and rubrica vetavit means, It is forbidden by the civil laws.
The praetor's laws were inscribed in white letters as Quintilian informs us (xii. 3 “proetores edicta sua in albo proponebant”), and imperial rescripts were written in purple.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894