The highest karat version of rose gold is also known as crown gold, which is 22 karat. Eighteen karat red gold may be made of 25% copper and 75% gold. For 18 karat rose gold, typically about 4% silver is added to 75% gold and 21% copper to give a rose color. 14 karat red gold is often found in the Middle East and contains 41.67% copper. High-end flutes are very commonly made of solid rose gold, the most common alloy being 14K.