The color of gold is determined by two factors:
1) The type of metal alloys included
2) The percentage of each metal alloy
Natural gold and color-saturated alloys are what give yellow gold jewelry its rich shine. The alloys most commonly used, are copper with a red hue, and silver featuring a green hue. An expert mixture of copper, silver and pure gold gives this precious metal its signature warmth.
A silvery white character is what makes white gold jewelry so appealing. In order to make the gold white, it is combined with metal alloys that are white in nature and plated with an extremely hard element called rhodium. Although strong, rhodium may wear away over time. Replating is a simple process that can be done to restore whiteness to your jewelry.
PINK (ROSE) GOLD
The beautiful pink hue of rose gold jewelry is created by using a copper alloy. Again, the overall percentages of metal alloys is the same for rose gold as it is for yellow or white, there is just a different mixture in what alloys are used.