i need color scheme for the cromwell i need them fast to

There's only one colour for the Cromwell, SCC15 Olive Drab, the British version (commonly called Khaki Drab) overall (though you could do a whitewash coat over it). Tamiya do it as XF-51, or go here to find other brand (Humbrol) colour mixes, MAFVA

in theater cromwells were only painted in khaki drab, with some whitewashed in winter.
some cromwells used for training in britain wore mickey mouse camoflage, but none of these saw service overseas
hope this helps
cheers
joe

This may be to late, but check out this tread over at M/L

http://www.network54.com/Hide/Forum/thread?forumid=47208&messageid=1064518259

Also may be a little late, but I have had great results using 80% Tamiy's Olive Drab and 20% Tamiya Dark Yellow for British Green. Like greatbrit said, they were more on the khaki side of green. Give the mixture a try.

Cheers

Rob