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.
A tyrant (Greek ÏÏÏÎ±Î½Î½Î¿Ï, tyrannos), in the modern English usage of the word, is an absolute ruler unrestrained by law or person, or one who has usurped legitimate sovereignty. Often described as a cruel character, a tyrant defends his position by oppressive means, tending to control almost everything in the state.