To accurately describe colors for color matching, especially when we delve into    the world of digital imaging and color management, we need a more reliable  method. In order to describe a specific color, we need to break it down into three    elements:

Hue: the name given to the color itself. This is defined by the name given to the main wavelength contained within the color, such as blue, green, magenta, and so on.

Saturation: (or chroma): the purity of the color. In many instances, especially in print or pigments, mixing black, gray, or white to a color will result in lower saturation.

Luminance: the brightness of the color. In pigments or print, this describes how much incident light the color reflects; in the case of a light source, it describes how much light is emitted.

By using these three measurements, any color can be described so that it can then be recreated accurately throughout an imaging system. An understanding of these measurements will help you to understand the relationships between the colors in the scene that you are photographing and how these will be reproduced in the final image.

To learn how manipulate colour balance using the Hue/Saturation Tool in Photoshop.

By Chris Rutter, “Color Theory Fundaementals for Digital Photography”