True colors of Mars - Hubble and USGS
True global colors from Hubble:
http://oposite.stsci.edu/pubinfo/pr/1999/07/extra-photos.html
True color of surface by the USGS:
http://photojournal.jpl.nasa.gov/cgi-bin/PIAGenCatalogPage.pl?PIA00982
Article on Martian colors in space.com
http://www.space.com/news/red_planet_991129.html
Colors of rocks and geology:
http://geology.asu.edu/~sreynolds/azvt/mv_color_rocks.htm
