shocking, right?
You may or may not know, the Doberman breed comes in four "acceptable" colors: black and rust, red and rust, blue and rust, and fawn and rust. The Doberman Pinscher Club of America has a page, and chart, on Color Inheritance, if you're interested. I remember drawing those squares back in seventh grade science class! In short, though, Black is the dominant color. Red is the other primary color (for lack of a better word. Black is dominant over red, however). Blue is a dilution of the Black Dobermans, and Fawn is a dilution of the Red (sometimes referred to as "brown", depending on who you talk to).