Painting realistic fur

as said up above, start dark and work to a lighter color. Break up your colors though....look at your dog or cat. I have a black cat but in sunlight he has distinct black rings around his tail and his fur almost casts a blue-black tone.

Break up your colors as you blend up through each color. Depending on what you are doing (lion, cat, Wookie) touches of orange, umber, purple or blue applied BEFORE your final layers of drybrushing/ wetblending will give you much more realistic hair tones.

 HTH

David