Stars like holiday lights...

Ask most people what color stars are and they'll say "white." And indeed, most naked-eyes stars are white or blue-white.

Amateur astronomers can tell you that you can also see yellow, blue, orange and red stars, if you know where to look. With binoculars or a small telescope, you can also see green stars.

But it takes Hubble to see something like this:
http://www.nasa.gov/multimedia/imagegallery/image_feature_1465.html