Natural colors can be extremely valuable, even in the very common yellow hue. A vivid fancy yellow in a very large size could easily be worth more than the house you live in. At the other extreme, light fancy yellows, are very moderate in value because of their abundance. A high saturation level is very important to overall value because of its rarity and general appeal. A fancy vivid yellow is a very valuable color, but add a touch of brown and its value drops to a fraction.