They are called white dwarfs because when they form, although not replenishing their energy supply any more, they are still hot enough to shine. Overt time (a long time) however, they will cool down...
Yes. When they are first created after a "normal" star ends it life, they are white because they are very hot. Over time they will slowly cool and in doing so turn from white to yellow, to orange,...
A white dwarf, also called a degenerate dwarf, is a small stellar remnant composed mostly of electron-degenerate matter. Because a white dwarf's mass is comparable to that of the Sun and its volume...