Lab color space is a 3-axis color system with dimension L for lightness and a and b for the color dimensions. Working with the Lab color space includes all of colors in the spectrum, as well as colors outside of human perception.
The Lab color space is the most exact means of representing color and is device independent. This accuracy and portability makes it suitable in a number of different industries such as printing, automotive, textiles, and plastics.
Although the Lab color space is the most exact representation of color, it is not the most commonly used. Lab color is usually converted to less accurate color spaces, such as RGB and CYMK, because computer monitors and printers use either three or four colors to represent images.
For more information on Lab color, see the Image Processing Toolbox™ documentation.