Clownfish color loss

[marioannou]

I got two black ice snowflake clowns about a year ago. One had a darker orange and one was lighter orange. The lighter one lost all it's orange and became black within a couple months. Didn't really mind because it helped tell them apart and looked good. However, I'm starting to notice the other one is started to get darker in some of it's orange spots. Just want to make sure nothing is wrong. Pictures are attached from when I first got them and now. It usually starts by the back area, but I also see coral sting marks on the clown that's losing color both times.

 

[Webslinger]

that's what happens as some mature