The classes all count the same. You can take the classes for your AA in the first 2 years and complete all your prereqs. then transfer for your BSN and it will be take you the two years. You still can follow the same path as the 4 year college. Either way you still have to take the prereq. classes.
Blue stars are the hottest whilst black dwarfs are the coldest. (However, no black dwarfs exist yet - see related question) The stellar classification [See link] in order of temperature. Our Sun is classed as yellow.
After years of cataloging stars, they were divided into 7 basic classes: O, B, A, F, G, K and M. Note that the spectra classes are also divisions of temperature such that O stars are hot, M stars are cool. Between the classes there were 10 subdivisions numbered 0 to 9. For example, our Sun is a G2 star. Sirius, a hot blue star, is type B3. Why do some stars have strong lines of hydrogen, others strong lines of calcium? The answer was not composition (all stars are 95% hydrogen) but rather surface temperature.