A video of the Dawn mission to the asteroid Vesta can be seen at www.jpl.nasa.gov/video/index.cfm?id=1085 and see the image of a multi-coloured asteroid Vesta at www.jpl.nasa.gov/news/news.cfm?release=2012-156
See also www.sciencedaily.com/releases/2012/06/120606210523.htm … same image and story.