Sneak attack damage and spell element damage

[Jeff Clem]

A sorcerer/ rogue cast Ray of Frost( 0 level spell) against a flat footed opponent, does the sneak attack damage take on the aspect of the spell element?(cold)? Second part, would the damage count as a whole against DR?

[Are]

Yes; just like a sneak attack with a longsword is slashing damage, while sneak attack with a club is bludgeoning damage.