1 yr update. The conch has been a role model tank citizen. I moved some of the loose smaller items that I would be worried about getting knocked over. He pretty much hides and pops out occasionally. Few times I thought he was dead since I could not find him but he eventually appears a few days /weeks later. Occasionally I can hear him knock the shell against the glass. But no issues so far.
The shell is typically quite pale and striped. Common colors include pink, cream or yellow. Looking at your opic again, may be a strombus snail which is very similar