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.
Contemporary academic usage of the term regime is broader than popular and journalistic usage, meaning an intermediate stratum between the government (which makes day-to-day decisions and is easy to alter) and the state (which is a complex bureaucracy tasked with a range of coercive functions)..