Tomorrow I will post examples of "muddy" areas in a painting and the same areas "fixed" in a recent watercolor painting. I have to wait until then to photograph with enough light to be illustrative.
David Leffel was interviewed on Artist Mentors on Line (link). It was a fascinating interview. In it, he discussed ideas about painting. He also defined "muddy colors " and "overworked" paintings. He described "muddy color" as "a color that one can't identify what the color is". He said the same "muddy" color painted as a small isolated square is no longer muddy. His definition of an "overworked painting" is similarly helpful. He defines an overworked painting as one that lacks a strong focal area. The "overworked" painting has the whole painting pulling the viewer's eye from one place to another, seeing all the pieces of the painting, all the colors, all the textures and that makes the "eye overworked". His rescue for an overworked painting is a strong place of focus. I may have an example of that before and improved also.