My husband found some oil based barn red paint at Mennards, no clue what the brand was but it covered much easier (if mixed well one coat works) than any latex paint and I'm suspecting it'll last a looooong time. Of course, it also took FOREVER to dry!
As an fyi... we painted a room inside using a Behr Latex in a shade of red, it took 4 coats even with the tinted primer, when we used shirwin williams paint (similiar color) took only 2 coats -- I'd def. pay the extra $$ for shirwin williams whenever using one of those more difficult colors, fewer coats = less paint used and less hours of labor!.