Documentation Link

https://matplotlib.org/2.1.2/api/_as_gen/matplotlib.pyplot.plot.html

Problem

The documentation explains the line style marker. After listing format string characters and single-letter color abbreviations, it goes on with:

In addition, you can specify colors in many weird and wonderful ways, including full names ('green'), hex strings ('#8000'), RGB or RGBA tuples ((0,1,0,1)) or grayscale intensities as a string ('0.8'). Of these, the string specifications can be used in place of a fmt group, but the tuple forms can be used only as kwargs.

The first sentence suggests that you can use full names, hex, and RGBA tuple strings in addition to the color abbreviations in a format string.

Suggested improvement

Possible rephrase:

In place of a fmt group, you can specify colors in many weird and wonderful ways, including full names ('green'), hex strings ('#8000'), or grayscale intensities as a string ('0.8'). You can also use RGB or RGBA tuples ((0,1,0,1)), but the tuple forms can be used only as kwargs.