Are Our Platy's Sick?

We have three platy's in our main tank which have been moved to our hospital tank.
This is due to two of them having a colour change on part of their bodies. This starts at just below their top fin.
When you look down the length of their bodies, you can see what is like a sheen running from where the patch starts to their tail fins.
Are our fish sick or is this normal?

Tank parameters are normal, but the only thing I would say is that one of the platy's had been trying to rub up against a german blue ram in the main tank when Lynda noticed the patch.

If they are sick, any ideas on what it can be and how it can be treated please?

I have attached two pictures to try and show what I am talking about - apologies for the quality but as you know, most fish won't pose for the camera.

David

Are there any round holes that they could have got stuck in?

Sorry, David. But I can't help you much. But I can tell you one thing that I THINK. I think that your fish were injured in some sort of tube or something. THis is a very dumb question, but have your fish ever been sucked up in a filter or anything?? OR what about one of those gravel vacuum things??

Are there any round holes that they could have got stuck in?