As the other person mentioned they have been seen with brown or black grips. Personally, I do recall seeing the original steyer imports, up thru the century, I've never seen anything other than black pistol grips on factory built ak's.
I have seen pics of Egyptian soldiers with brown gripped ak's, but not one brown gripped ak in any US retailers shop. On a side note, I did see a gun show peddler selling the black grips seperately(marked up), and brown grips in the few kits he had. Not sure if he pulled those, but I felt he did.