Gem diamonds in the D-to-Z range usually decrease in value as the colour becomes more obvious. Just the opposite happens with fancy colour diamonds: Their value generally increases with the strength of colour and purity of the colour. Large, vivid fancy colour diamonds are extremely rare and extremely valuable. However, many fancy diamond colours are muted instead of pure and strong.
Fancy colour diamond engagement rings are available almost any colour you’ll imagine. Red, green, purple, and orange are generally the rarest, followed by pink and blue. Yellows and browns are the most common fancy colours, but they’re generally more affordable than the rarer colours. Blacks, grays, and fancy whites are considered fancies, too.