How do I create different colors of gold?

I was asked some time ago how different colors of gold are made.
It is known that there is gold in yellow, white and rose color. There is even green, blue and purple gold, but it's really rare.

So what makes yellow gold yellow, rose gold red, and white gold white?
All the difference is in the mixture of the extra metals added to the pure gold and the ratio between them.

In yellow gold, copper and silver are added to the pure gold, usually in equal proportions.

In pink or red gold a lot of copper is added and a little, if any, silver.

White gold has several options - if you add palladium and silver, it creates a soft gold that is easy to process and does not cause allergies.
If you add nickel, copper and zinc it creates hard gold, which is difficult to process. Sometimes this alloy causes allergies because of the nickel.
White gold is not really completely white, but a bit yellowish, so it is common for white gold jewelry to add a rhodium plating that gives it the white color.

I have attached below a picture of one of my models in different colors of 14K gold- on the front it is yellow gold, in the middle white gold, and on the back pink gold.