No not common. To my knowledge it would not have left Colt without a label. Even the Custom Shop had their special labels. You probably have an after market replacement box. Pictures would be needed for a better answer.
Beautiful gun. The box does look like a Colt original. Strange no label. Possibly returned to Colt (with out the original box) for some repair (not Custom Shop) and returned by Colt in a Colt box but not original to the gun. There is no way to verify the gun and the box started life together so the box adds very little value to the gun. IMHO