*Feels lame for this but has to point it out anyway*
Kaito is just a name and as far as I know doesn't mean phantom. Kaitou means a phantom/gentleman thief in Japanese pop-culture... but whatever.
And to say a purple anything you would say murasaki no -insert item- so it would really be murasaki no Kaito. but again, whatever. Just had to point it out because I'm anal like that Dx