What is the ruling on wearing a watch that contains white gold, and is white gold artificial and not natural?

Summary of the Answer:

If white gold is yellow gold that has been treated to become white, then it remains gold and takes the same rulings as yellow gold regarding its prohibition for men to wear. As for platinum, it is not gold and does not take its rulings; it is permissible for men to wear it, and people's calling it "gold" does not change its legal ruling.