I brought some a few months ago from ebay, just ahd a look and the seller no longer has any more. If it helps the auction name was: 4 x BLACK Nissan 54mm/55mm Alloy Wheel Centre Hub Caps Micra Note Qashqai Juke
I have the OEM wheels, not sure if the Rays are the same size.
Simplest solution is to just paint your own or ask the wheel refurbers to do it for you, can't imagine they would charge much. The nisan logo will pop off if you melt the pegs on the back of it, then just glue it back on after painting.