One idea about the (brightly) colored versions of the Pentax K-x:
Insurers have noticed that brightly colored or off-colored (pink, light green, golden) cars are less often subjected to theft than more common colors (black, grey, etc.). This probably comes from the fact that they are less easy to sell again.
So, why not choose a Pentax K-x of the brightest possible colors to limit the risk of theft?
Source: FamilyHomeSecurity.