One can make a color-color plot by arranging stars in a two-dimensional graph, where each axis measures a different color index. Below are some examples from the SDSS, which uses a set of broadband filters called (u, g, r, i, z); they are very roughly equivalent to (U, B, R, I, _).
regime - the organization that is the governing authority of a political unit; the government reduced taxes; the matter was referred to higher authorities. authorities, government.
C14: from Latin: guidance. Word Origin and History for regimen. n. c.1400, medical, course of diet, exercise, etc. for sake of health; mid-15c., act of governing, from Old French regimen (14c.), from Latin regimen rule, guidance, government, means of guidance, rudder, from regere to rule (see regal).