You cant imagine how much better I feel each time I read it's common in orange tabbys! At first when I noticed them I was horrified they were something dreadful, but soon realized it wasnt spreading to the other cats. And I thought maybe my vet was just poo pooing me off when he said they were nothing to worry about....
So, thank you everyone for my peace of mind!

heidiv, thank you for the advice on keeping a close watch the eyes