OK, this is very strange. Our baby is 9 months and 1 week old and in the last couple of days he has sprouted 2 new teeth - the two next to the top middle 2 (so he now has 6 altogether).
The one on the right hand side, though, is BLUE. It isn't completely through the gum yet, but the bit that has appeared is definitely blue.
What on earth is this and does it matter??? It doesn't seem to cause him any discomfort, apart from the usual dribbling and red cheeks that go with the new teeth anyway - but we have tried pressing it gently with a finger and also brushing it with his little toothbrush, both of which he through was great fun and didn't cause him to squeak or yelp. But it is still blue....