Yellow gold can be polished to maintain its shine.
Use a gold polishing cloth or have it professionally polished.
Do not use abrasive cleaners or materials which can scratch the gold.
White gold is often plated with rhodium to enhance its white color. Over time, this plating may wear off and need reapplication. Take it to a jeweler for re-plating as needed.
Clean with a mild soap solution and a soft brush. Avoid using ammonia or other harsh chemicals.
Use a mixture of mild soap and warm water. Soak for a few minutes, then gently clean with a soft brush.
Buff with a soft cloth to maintain its luster. Avoid harsh chemicals as they can affect the copper content in rose gold.