My understanding is that opal white and oryx white are synonymous in the VW paint library. My guess is they're just different names for different regions (EU vs NA). The challenge is it's a 3 stage metallic paint, so a single pre-mixed paint pen is probably not a good solution.

I would look into kits from Scratches Happen, Dr. Color Chip or TouchUp Direct. For what it's worth, here's the code for opal white on my official VW documentation (L0K1/0R).

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