IMO
Silver looks good with silver wheels..
Black X5 depending on Wheel type and wheel color can make the car or break the car..
personal opinion i guess and what you want your car to be....
But on your Wheels since you have style 87's ....id go lighter than Black....not unless your going to drop the girl...lighter would be good..since your wheels are concave..it will make it pop with lighter color and throw some spacers there and BOOOM!....your set!.