I really dislike the color wheel for picking certain colors, especially browns. I would really like a few more options to pick the colors. A large amount of swatches would be especially nice. Now I often go to a site listing color codes and copy paste these into Blender, which is a laborious process.
Perhaps you like one the options better:
You might be also interested in the Palette addon which only works only in paint modes (Image Painting, Texture Paint, Vertex Paint, Weight Paint)