WHITE GOLD
For an 18 carat gold (750/1000) you can have different colors. The gray color can be obtained with an alloy of 75% gold and 25% mainly silver and/or palladium.
In watchmaking, white gold is mainly used in the case and bracelet. It is appreciated by a certain clientele because it is gold but it is not visible. Some watchmakers give it a layer of rhodium on the surface. This makes it whiter and also harder on the surface. The disadvantage of this is the management of the repolishing in the after-sales service which becomes a little more complicated. Other houses leave the white gold without rhodium coating, so it is a little bit greyer but easier to manage in after sales services.
Advantages:
Gold has the advantage of being stainless, which makes it a sought-after component for dressing. Moreover, historically gold has always had a role of excellence and rarity, associated with luxury it represents an important asset for a collection. The fact that gold can move in different colors allows a wide variety of colors for a model.
Disadvantages:
Gold has the disadvantage of being heavy. It is also sensitive to expansion under heat. Secondly, gold is soft and therefore can be complicated to machine, which is why it is almost never used in 24 carats but rather in 18 carats, which somewhat neutralizes its defects. If too pure, it can be sensitive to damage (shocks, scratches). The extraction of gold can be harmful to the environment depending on how it is done.