What? No! That converts into a Wizard real easily! Are you willing to re-flavor? All those spells are Wizard spells. See: Ray of Frost: level 1 at-will. Detect Magic and Knowledge: Arcana are both the Arcana skill. Color Spray is a level 3 Wizard encounter power. Dancing Lights is the Prestidigitation cantrip. There's a feat that lets you summon a familiar and spells to summon other creatures, but it's in a book I don't have. There's a feat that gives you more damage with your cold-based spells. Just have him refer to himself as a Sorcerer all the time. Doesn't matter, the flavor can be whatever you want it to be.
The biggest change you'll find is that Wizards don't have to carry around crossbows in 4e. He can cast Ray of Frost as many times as he wants.