Hello. I have an adult male yellow bellied slider who is well looked after and has always had very bright, very prominent green and yellow striped skin. However over the last 6 months or so he has developed faint brown spots, kind of like a mottled effect, all over his skin and plastron. He seems completely healthy and is eating a balanced diet, his water temp and conditions are as advised. I have researched shell rot and he doesn’t have any other symptoms other than this weird discolouration. I don’t know if it’s just because he is getting older? Does anyone know what this could be??? Is there anything that I can try to make this go away?