Hue is your first impression of a gem’s basic color. It’s the green of a tourmaline, or the blue of a sapphire. Hue might be described as red, orange, yellow, green, blue violet, or purple.
A hue wheel can help you visualize the range of possible gemstone colors. Gem colors are often combinations of hues. For example, blue sapphire’s hues can include both violet and green components, and ruby’s hue often have a touch of orange or purple.