When i got my bmw, the 2 right alloys were badly...i wouldnt call scuffed rather then chunks out of. A local dent repair/alloy refurbisher fixed them up and i couldnt even spot where the scuff was afterwards
touch up with rover ' stone grey' paint its a perfect match. I bought some just in case. I beleive other 182 owners with anthracite wheels have used this.
btw got it in a spray from halfords. Just spray into the cap and use a brush to touch it in.