Color, saturation, hue, lighting, are all excellent.
Focus is lazer sharp. Depth of field is a little shallow as shown by the blur on the end of the drop.
The picture is a little under exposed for my taste. It makes the pastels a little dark. I would have liked to have seen details on the brush bristles all the way down. They appear to dissapear into the black background a little above the bristles.
Very nice composition, and staging. I really enjoyed this picture.