The CIE L*a*b* (or Lab) colour model is the most widely used type of luma-chroma model. Its L axis is associated with the luminance of the colour, while the a and b axes are associated with green-red and blue-yellow respectively.

Since the CIE L*a*b* model is both a widely adopted standard, as well as a device-independent model, there exists only one colour space implementation of it. For this reason it is not entirely clear whether it counts as a colour model, a colour space, or both.

The Grasshopper colour picker provides access to the L*a*b* space.