Yeah, but only because you can't really have "shades" of black. The CSU and AfD are both indicated as blue the same way the SPD and Die Linke are both indicated

Yeah, but only because you can't really have "shades" of black. The CSU and AfD are both indicated as blue the same way the SPD and Die Linke are both indicated as red, but usually different shades (or e.g. using magenta for Die Linke, which is even sillier as Die Linke is to the left of the SPD). Every party has an official color of course, but they're not always used in reporting. For example, while the CSU uses blue for its logo, the CDU uses red but still is traditionally represented in black.