Amazon, here are some i found if you want
Kingray Jewelry Two-Pack, 3mm Black White Polished Ceramic Wedding Band Stackable Ring Enhancer https://www.amazon.com/dp/B07JPB3C8G/ref=cm_sw_r_cp_api_i_QN5Y3SXCBWARS5P0CFJZ?_encoding=UTF8&psc=1
MJ Metals Jewelry Ceramic Wedding Band Classic High Polished Ring Varying Colors and Widths to Choose from https://www.amazon.com/dp/B01N28AJ9G/ref=cm_sw_r_cp_api_i_YJ03B0FFZXNVCZMVXTC3?_encoding=UTF8&psc=1
This is such a clean and classic look, if you’re willing to look at a ring guard or double wedding bands, the symmetry would probably look amazing! Something like this Blue Nile band or similar could be nice on one or both sides.
I can’t quite tell but it looks like the milgrain is white gold...if it is, you could probably have a two-toned band set made to fit next to the ring perfectly and emphasize the setting! This ring guard - sorry for the Amazon link - would be fun if you wanted higher impact and the two-tone look.
We were super nervous about buying a ring off Amazon, but it couldn't have turned out any better!