Not sure. Take a look at paint codes PMTG (dolphin grey), or CX ( Ford Dark Shadow Grey Metallic ).
Paint does not stick long term to bare aluminum without an etching primer. For curb rash, instead of primer, I have used 5-second UV curing glue kit, because it sticks well to bare aluminum and acts as a filler which can be wet sanded easily and painted over. The UV glue can be added repeatedly to add more fill if necessary after wet sanding.