Dark Oil streaks on front nearside rim...??
 

Brakes were all recently serviced + new calipers, pistons I then collect the car from garage, drive 20 miles, park and notice dark black oil streaking (looks like engine oil) streaked across the rims by centrifugal force.
There are 8 or so black streaks about the width of a matchstick across the width of the right hand (drivers side rim only)
Any thoughts ?
Cheers
Rich

It doesn't seem to be alot. Could be residual brake fluid, cleaner or lubricant from the brake work. Examine that side of the wheel for obvious wet lines, fluid leaks etc. Wipe off the wheels and see if it retrurns. Though the shop should stand by the work, so you may want to take it to them first for a look.
regards,
Steve

Grease
 

Called the garage >>The garage were so worried they drove over to my home to check. There is thick black grease from behind the wheel nuts ....
And as the rain yesterday and the centrifugal interplay caused the fan effect around the rims>> Thanks !
Rich

It may be the lubricant they used on your alloy lug nuts to keep them from seizing up. Alloy wheels and alloy lug nuts can fuze together if there's not a lubricant between them. If the lubricant is put on too heavy it will throw it circumferentially toward the rim. I have white wheels and after every tire removal, whether for bleeding brakes or tire change, it's always there. Just clean it off and watch it to ensure it goes away. Frequent washing with soap and water will dissolve it. They must have really put a bunch of it on there, if that is in fact the problem.

Looks like brake dust after its been wet. new pads? Could have gotten wet during service. Brake dust from back part of the wheel.