Ideally, have the cherry crown and the white crown done in the same profile. Then you put the cherry crown on top of the cabinets, and they meet the white crown that runs the perimeter of the rest of the room.
I would not do cherry crown moulding all over the kitchen, nor would I top the cherry cabinets with white crown moulding.
If you have two different crown moulding profiles selected, then ask your carpenter if he can transition them somehow, or else have him "end" the white crown a couple of inches shy of the cabinets (not the ideal solution, but it all depends on the crown moulding selected)
If the cherry moulding is smaller profile than the white, I.e. if the white crown is bigger in adjoining rooms and you want it all to flow), then I would do the white moulding in two pieces....one to match up perfectly with the cherry, and then you add a second trim piece just below the first, and paint it all out to look like a bigger piece of white trim.
Gee, I hope that makes sense....I'll try to find a visual for you!