The rare Columbian 4 cent Blue Error fleet of Columbus was printed in Ultramarine.However a small number of 233a were printed by Error in a rich lovely blue.In my photo scan the stamp on the left appears to be a standard 233,and the stamp on the right appears to be the Sc#233a blue Error? Does anybody know? Eventhough the stamp on the right is slightly damaged.It appears to be the 233a..
