Gold comes in different karats and color forms. The most often used colors of gold are white and yellow gold. We can count on several differences between these types including their advantages and disadvantages.
These two kinds of gold weigh the same as far as the karat is concerned. One difference is their mixture of alloys in order to make them strong as pure gold is soft and pliable. Yellow gold is a mixture of pure gold and alloys of copper and zinc. White gold, on the other hand, is made out of a mixture of pure gold and some white metals like silver and palladium.
Nickel used to be mixed with gold traditionally, however ever since it was discovered to cause allergies on human skin, its use was eventually avoided.
White gold is chosen widely by many people due to its silver color than that of the yellow gold, even though it is sometimes more expensive when it is mixed with platinum or titanium. White gold is scratch proof compared to yellow gold taking into consideration the alloys with which it is mixed. With rings, white gold is mostly preferred as it complements the color of the diamond while yellow gold creates the illusion of a yellow tone in the diamond stone.
White gold made with nickel could be an allergen. Its color appears to be faded. It sometimes is paired off with rhodium in order to give it a "shiny" effect, but rhodium fades and wears off. Therefore you have to re-plate it each time it wears and it would cost you extra.
While white gold fades, yellow gold has this classic color for rings. In fact, older gold rings are much better looking than the newly made ones - it is due to its components. Yellow gold does not require the need to be re-plated - so there is your savings. There is also a lower risk of allergic reactions.
Yellow gold would look nice with people with warm skin tones but would make people with cool skin tones look pale or washed out.
The only thing that makes these two types of gold the same is their being "pure gold" and by being exquisite when put in jewelry form. They are both good choices.