Whenever you start a new and different Martial Art, I believe you should always start a fresh. Not only can you get away with doing things wrong, it gives you time to re-learn how to do things differently that you are already programed for.
I say embrace the white belt :)
I've started back at Taekwondo recently after a few years off and I'm not wearing a belt (effectively appearing to be a white belt) until I feel ready to wear my normal belt - so I definitely agree: embrace the white belt.
We've had guys train with us that have done other martial arts and they always and without fail start at white belt. If they got to a senior grade in a previous art (think near black belt or black belt) then they may double-grade or grade quicker, but they always start at 0, same as every body else.
Good luck with your JKD.
