What code do I need to run to get Python to recognize the preset colors?

My syntax all words fine until I add the color =
I get this error:

~\anaconda3\lib\site-packages\matplotlib\colors.py in to_rgba_array(c, alpha)
    365 
    366     if isinstance(c, str):
--> 367         raise ValueError("Using a string of single character colors as "
    368                          "a color sequence is not supported. The colors can "
    369                          "be passed as an explicit list instead.")

What do code do I need to run that I must have missed to get the preset colors?