Another gerbil color question

[Shelley and Don]

I have a question on gerbil color(s). With everyone's help here on the list, I think I've accurately identified our pup's colors -- we have 3 agouti and 3 light colorpointe agouti is what I think we have... and they are all doing great and almost 6 weeks old. We found a really great pet store that is waiting for them as soon as we feel they are old enough and nice and tame so we can be proud of them... (except we are keeping one that was sickly with a respiratory problem earlier on and needed antibiotics as we have grown attached to her -- "Bambi" is her name).   The question I have is regarding the "white" pups... since they were born, they seem to have some kind of a real light brownish/coffee color like a "stain" is the only way I can describe it on their fur and it is on their heads and down their back. But like I said, it is very very faint, barely noticeable. Does anybody know what this is and if it will fade or if it will stay?   Thanks in advance for all your help.   Shelley Baker