I'm not too sure what to think of it really. Maybe because I'm so used to seeing them WITH the running board and mudflaps it just makes it look a bit odd to me.
I agree with Falls on the mudflaps though. Big paint chip savers and they really dont look bad at all.
On your white truck, what I think would look cool, would be to have a tube step painted to match the body, and on top of the tube step, have a full length diamondplate cover, coated in black Rhino Liner. I think THAT would look sweet on a white 4Runner IMO.