Mothers side: pure Dutch.
Fathers side: Who the hell knows. My fathers ancestors were gypsies until two generations before him (and pirates before that, if my grandfathers tall tales are to be believed). Half of Europe? What I do know is part German, Polish and Norwegian.
I've been told I look more Polish than anything else, but I pass for native Dutch, German and Belgian as well. Then again, those are just varieties of caucasian, so it's all a bit vague.