When gerbils molt their fur do they change their fur color?

My first grey gerbil which was grey befor molting always had a white spot on his head and between his shoulders but now he's tuning all the way white... My other gerbil is an original golden tan color which fads to a creamy tan color on his belly but now he's loosing his tan and tuning to a cream color... Is this normal and does the molting process correspond to a gerbils natural color pallet or does it randomly pick a color