Underside turning pinkish

Just moved one of my rays from a tank that was mostly bare bottom to a tank with some peace river gravel and i've noticed that the underside is kinda turning pink like it's irritated. she's eating normall and moving around like she's alright but I'm worried that it'll irritate her and I fear infections. Is this normal when moving rays from bare bottom tanks to gravel?

K, I'll keep an eye out. Thanks Fishdog.

What would an abrasion look like? bright red?

I was worried at first because the gravel was sticking to her disc and I was worried she was losing her slim coat. But as of this morn, she is swimming around happy as can be.