Chroma is hard to separate from lightness. An important painting point is that mixing paints cannot increase chroma. Instead it tends to reduce it towards muddy grey.
Although lightness and chroma can usually be approached successfully using methodical approaches, long experience has shown that hue is much more hit or miss. Developing a good ‘eye’ for colours is generally much more important.
Lightness is key to the depiction of materials, textures, edges, and form. Illusions can confound the viewer, and it is vital to map the lightness of your motif to that of your painting.
What do we actually perceive of colour?
If we are to understand colour in painting, to comprehend how to apply pigment to depict what we see, we first need to understand our perception of colour.