Changes in a kitten's fur, seasonal?

Hi, i'd like to get your thoughts of what this is all about before i go to a vet with such a silly question.
My adopted stray of about 2 mos. has gone from jet black and white to having an undercoat of gray. The change is 'dramatic' because the longer, silkier, outer coat *seems* to now be getting replaced with this downy gray layer underneath so much so that you can see stripes for the first time in the black and the black fur looks "thinner" and much less dense.
Seeing as how we in the southeast US have been just granted a 5 degree "reprieve" from a heat wave, and she spends 99% of her time indoors in the a/c, the change from summer to fall-ish, doesn't seem to explain it to me, (it's still HOT) but i know nothing of their internal rhythms/cycles.
Is this just a stage i missed out on in previous kittens? I've normally adopted older cats.
She is perfectly healthy, she is energetic and eating extremely well.
There are no bald patches, skin changes, broken skin, scratches, parasites, or *any* other signs/symptoms. Just a weird new fur look lol for her

How old is your cat and what type of cat is she? Does she have long hair or short hair? Some breeds of cats will have their fur change as they grow. It is hard to tell without actually seeing your cat. Have you brushed her? Cats do have undercoats and this is what sheds off.

Hi! Welcome to TCS! If she is young, she may just be losing her kitten coat, which they will usually do around 3 months of age or so. Since she was a stray, it could be from the better food and love she is getting now, since diet and stress affects their coats. Have any pictures?? We love photos here!!

Thx for quick replies Ok, she's about 2 mos, but no more than 3 we think, and she's a shorthaired domestic. I have some kooky shots from about 4 weeks ago that don't show the changes..I will have to take some asap
Yes we brush but there's not much there to get up into the little bristles, if that makes any sense. The undercoat is superduper short. Umm, how do i insert a pic or do i have to link it?

Then she is probably losing her baby coat. Here is a link that explains all about posting pictures of your sweetie!!

http://www.thecatsite.com/forums/showthread.php?t=14474