| White gold is an alloy consisting primarily of gold, mixed with other white metals, so it doesn't have that characteristic golden color. It is a popular choice for wedding bands, in that it is considered more valuable than silver, whilst being more reasonable pricewise than platinum when comparing the different white metals.
White gold comes in the same carat counts as yellow gold, and carries an identical percentage of gold. For instance, 18ct yellow gold is 75% gold, and 25% other metals, added for durability. Usually copper and/or zinc are used for this purpose. 18ct White gold is still 75% gold, but the other metals are usually things like nickel, silver, and palladium. It's only the alloy mix that changes. Brand new white gold jewelry is plated with Rhodium, another white metal that is very durable. However, it will wear off. White gold rings should be replated every so often to keep them looking new. | 
