Some folks like them painted some folks don't. I think of them as tools and a little paint won't hurt, other see them as works of art and a scratch, ding or
heaven forbid paint would surely deminish the masterpiece. One thing for sure, if you paint it and it'll get remarks.
I'd go for the big and little camo combined (near and far may be another term you may hear it called). Basically large areas of darker shades with light(er) intermixed and other large areas of light shades with dark(er) intermixed. A bit like this Rhodesian if you get what I mean.
http://www.tridentmilitary.com/New-Photos14/rrh08-b.jpg