Changing Hamster's name?

[Mweekie]

OK - this is a bit of a strange question - but can you change a hamster's name after owning them for just under a week?

Reason being is that Horatio's name doesn't quite suit him, I don't know why, but I keep almost saying the name Casper instead of Horatio, and when I did say Casper once, he looked up almost right away and nearly came over to me - he is still a little shy - whereas he doesn't always look up when I say Horatio.

He almost looks like a ghost as he's a light grey banded, with white and ginger just under his eyes - I definitely need to try and get a photo of him in his thread.

I don't want to confuse him obviously, but I'd just thought I'd ask this?

Mweekie xx