Hatchery RIRs (Production Reds, as any breeder will call them) aren't exactly bred to a standard. They're just bred to be very good layers of brown eggs. Personally, I love my Production Reds (the four I still have in the flock are still good layers and lay 4-5 a week in the summer despite being about four years old) Heritage RIRs (or true, bred to a standard RIRs) are a deep mahogany brown color.
EDT: so in short, yes, it is pretty common for hatchery RIRs to be different colors.