I have a small collection of 18ct gold jewellery, some 925/830 sterling silver jewellery, and quite a bit of yellow-gold plated sterling silver. I love yellow gold but unfortunately I have a sterling silver budget. Gold-plated silver often costs a little bit more than the same thing in plain silver, because of the extra cost of the gold plating.
Some yellow gold plating holds really well – I have Thomas Sabo and Vidal & Vidal gold-plated rings that I use all the time and they have not faded at all. Other gold plating fades almost overnight, just with normal wear. If you drive, wash your hands with your ring on, or use your hands a lot, the fade will happen more quickly. Usually the top of the ring is still fine, while the underneath goes paler and paler.
Because rings and earrings (if you wear them 24/7) take such a hammering, gold-plated bracelets and necklaces last longer. I have also found that gold-filled or rolled gold jewellery with a base metal of brass lasts better than some gold-plated sterling silver.
I would avoid plated yellow or rose gold sterling silver for wedding or engagement rings that will be worn 24/7, or for decades. In this case it would be better to have pure gold, or sterling silver (though 925 sterling silver is soft and wears down quickly).
The photograph above features a rather old round sterling silver gold plated ring by Thomas Sabo, and a gold-plated moissanite ring from AliExpress. I use these to ring the changes and both have worn very well. It’s hard to say which brands are hardier than others, unfortunately, because each company plates differently or in different thicknesses (microns). You often have to find out the hard way.