Yes you are covered for shrinkage and discolouration as there is an endorsement on the policy for CC treatment risk.
Problem is when I recently claimed Allianz the insurer didn't realise that HSBC had put this in!
Also I said to chappy thought my treatment risk was 500, he said no 250. Then he rang me back said I wasn't covered at all for treatment risk
He later rings back and said I was covered.
Apart from that they have been very good with this claim.