Pale brown spot on picasso trigger

[gallatea]

I bought a picasso trigger 2 days ago. He's doing great in my tank and looks really healthy, but I noticed he has a pale brown spot on his side (he had this since I bought him). It is somewhat raised and is pale brown. It looks like it could be a healing scrape as I've read that picassos often wedge themselves into corals/rocks to rest or whatever, but I'm still concerned. He is eating fine too. The spot today looks exactly the same, no better, no worse. Anyone have any ideas? Thanks much in advance. Jane

 

[gallatea]

The last pic looks like the spot is dark - it isn't. I took another. Also, I noticed his eyes seem to have this blue hue to them. Is this normal for a picasso. I had one long long ago, but do not remember the blue hue in their eyes. Thanks. Jane