1.925 sterling silver
Silver: does not fade. Due to lifestyle and personal physique, some people's sterling silver jewelry will be oxidized and blackened. You can clean it with a silver polishing cloth/toothpaste and toothbrush to restore the brightness.

Gold, rose gold: it will fade, the way to extend the color retention is to avoid direct contact with chemicals (perfume/detergent/skin care products), etc., you can flush it, but it is recommended to wipe it dry as soon as possible.

2.14k/18k gold plated
Will not fade, if the color becomes darker, wash it with dish soap to restore the brightness.

3. Brass/alloy
Silver, gold, and rose gold will fade. Vacuum plating can keep the color for a period of time. Avoid direct contact with chemicals (perfume/detergent/skin care products), etc., less flushing, and dry sweat and moisture in time.