Silver is the most available color in the used vehicle market -- more than 447,000 vehicles, followed by black (429,000), white (409,000), and red (321,000). Blue (309,000) and gray (277,000) are also aplenty. The color you're least likely to find? Pink, with just 249 used vehicles listed.
(Sources: VAST.com (vehicles available as of July 21, 2008), CARFAX, National Highway Traffic Safety Administration)