Black spots on white Devons nose?

I have a 3yr old white devon rex. She has always been an inside cat as she is deaf and i live on a busy road so i cant take the risk she will get hurt. She has always been a healthy cat but last week i noticed she has developed black spots on her pink nose. There seem to be 2 big ones and a few more smaller in size. Could anyone advise as to what this may be before i look at going to the vets?