Pimxa ip-4000 printer - black color on photos

Approx 24 hours after printing photos on the Canon Pixma ip4000 printer, the photos have a discoloration where there is a large amount of black colo. For example, the photos that have people with black hair, there is a discoloration on their hair - kind of becomes frosty looking. This discoloration is not there when the photo is first printed and oly becomes noticiable about 14-36 hours later. This only occurrs on teh black portion of the photo. I am using Premium Plus HP Photo paper, high gloss.