Gold-plated jewelry care:

To prolong the shine and longevity of your gold-plated jewelry, it’s recommended to avoid wearing when swimming (salt or chlorine water), showering, and sweating.

Cleaning your jewelry with a soft lint-free cloth every few months or once a year can help to keep its shine. (Note* Do not use a jewelry polishing cloth - these types of cloths are usually treated with a polishing agent and it can strip the gold plating, however, I highly recommend it if you have tarnishing 925 sterling silver jewelry!)

Warm water and dish soap can also be used to clean your gold-plated jewelry. Avoid anti-bacterial soaps.

Additionally, if you wear the jewelry regularly, your body oils actually help to keep the metal from tarnishing (this goes for sterling silver jewelry as well).

If you wear make up and perfume, try to apply this before putting your jewelry on - have your gold-plated jewelry be the last thing you put on before you leave, and the first thing you take off when you get home. The chemicals in perfumes and colognes can cause a reaction similar to oxidation and can potentially turn the gold plating black!

This information came from a helpful resource I found here !