The last three characters of VW part numbers can sometimes - but not always - be the paint code. The part number for Reifnitz alloys is 5G0601025EB Z98 and based on the above, Z98 ought to be the paint code. However, a search on ‘VW paint code Z98’ returns the colour Heron Grey which is a Porsche colour and a very light grey (almost white with a hint of grey) from the early 1960’s, so clearly it’s not the paint code for Reifnitz alloys.
If you’re wanting to buy a touch up paint pen to repair minor stone chips on your alloys, I’d be inclined to just get a universal, non VW-specific matte black touch up pen; it’ll probably be a close enough match even if it’s not exactly the same shade of black. I had some VW anthracite coloured alloys on a couple of previous VW’s I’ve owned. I couldn’t find the correct VW paint colour to repair a few small stone chips so ended up buying a BMW colour that was a close match. No one would notice the very slight colour mis-match and it was close enough not to bother me, and I'm pretty anal about things like that.
I’d be sure to get a pen with one of the hollow needle / nib type applicators on top of the cap, as it’s possible apply paint into stone chips with much greater precision with a needle / nib than it is with VW touch up paint pens. The VW pens always used to have an ‘oversized’ brush inside the cap (I’m assuming they still do), and for most minor paint touch up jobs you’d often end up with an unsightly paint blob if you used the brush.
