Gold is a naturally beautiful metal. It has lusters and colors that are unlike any other material. It is also very malleable making it easy to work with, but still durable enough to be used in men's rings. Gold has a high resistance to rust, tarnishing, and corrosion. It also doesn't fade over time. These characteristics along with its rarity are what has made it a popular choice for men's rings throughout the ages.
Yellow gold is naturally warm in color and is the normal color of gold. Depending on the karat (amount of pure gold) in the ring, it will vary from a light yellowish-gold color to a darker more pure gold color.
Rose gold has a pink hue to it, similar to copper. It is a gold alloy that gets its color by adding copper to the gold. Higher karat rose gold gets a warmer color to it and can start to appear a little less pink due to having more natural gold in it.
White gold has a silver-white color. It gets its color from mixing metals such as palladium, silver, and nickel into it to create the white gold alloy. It is also plated with rhodium to give it an even more of a white color. White gold doesn't vary much in color based on karat count.
The purity of gold is measured in karats. Each karat represents that the metal is 1/24th gold. This means 24 gold gold is 100% gold, 18k gold is 75% gold, 14k gold is 58.3% gold, and 10k gold is 41.7% gold. The amount of gold in the alloy can alter the color of the gold. You can see examples of the gold colors in the different karat amounts here.