The colour of the stars is an indication of their temperature, with blue being the hottest and red the coolest (everything is relative, of course!). As they evolve, the stars pass through different phases, and this changes their size and colour. In about 5 billion years (on a tuesday...) the sun will bloat up to become a red giant, probably big enough to swallow the Earth's orbit within it. Then, some millions of years later, it will blow off the outer layers, and the core will become a very small, *very* hot white dwarf.

Also, these stars are not likely to be more than a few dozen light-years away. Very few individual stars are visible more than a couple of hundred light-years off. If you get up into the millions, then you are talking about another galaxy, and you won't see individual stars in them - unless you discover a new supernova!