So glad you asked!!! Let's start with what is GOLD?
PURE GOLD - 24K gold is 100% pure gold, it is rich yellow and color and because of its purity, is way too soft to be used as jewelry. So what do we do to make it durable? Jewelers mix different metals and create a strong, gorgeous and long wearing masterpiece. 14K is probably the most common gold for jewelry. It contains 58% gold.
Let's talk color. If all gold starts as pure gold, then all the alternative colors from the metals that are mixed with them to give their color.
Yellow Gold: Silver, copper and Zinc are the metal alloys added to give 14K its distinctive color.
Rose Gold: Silver, copper and zinc alloys are added, but the ratios are different. If more copper is added, that warmer, pinkier color appears.
White Gold: Pure gold is mixed with copper, silver and palladium...but it's still possible to find jewelry also with nickel added to give it that distinct, "platinum" color.