Teeth in chameleon consist of bone, which can be somewhat yellowish or fawn, but regularly not brown. There might be slight discolourations, too, but that's really something to check up immediately due to big and long lasting problems with mouth rot in chameleons. Please take her to a reptile vet and let them check her mouth properly, which includes gently testing the teeth with a probe for fragility or any additional problems inside the mouth cavity. Sometimes you won't see any swellings outside, but the bone's alreay dissolving (as happened in this case). That's why "just taking a short look inside her mouth" is not enough. If your vet's not going to find anything horrible, fine, but I definitely would always worry about smallest discolourations concerning teeth.