Why people choose "boring" colors for new cars?
Mainly, because they're too noticeable. 

You don't really see houses in electric green, pink, or yellow. No one wants to stand out in a crowd or be the sore thumb.

Here: http://www.usnews.com/news/articles/2012/10/12/survey-americans-pretty-much-the-whole-world-prefers-boring-colored-cars

I'll post more sources when I can.