When gold is pure, it has a stunning yellow colour. When goldsmiths want to use gold to make jewellery, they almost never use pure 24k gold, but for example 18k gold which exist for 75% out of pure gold. The other 25% is an alloy. This alloy is needed to make gold stronger so jewels can’t be broken or bent.
When 18k gold has a white look, the 25% alloy is palladium, nickel or silver. When your 18k gold has a pink rosy tone, 25% is Copper. So white or rose gold is created by melting pure gold with another metal with a strong colour tone.
