I believe that either in 72 or 73 Ma Mopar switched from the black to the orange color. Its NOT the same shade of orange as the engines were. Its a little softer than street HEMI orange.
The factory sprayed them in large batches, so you know it wasn't from spray cans! YOU could though, with decent results, as long as you take your time and spray 3-4 thin coats with 15 minutes between applications.