Problem

https://matplotlib.org/stable/api/_as_gen/matplotlib.axes.Axes.stackplot.html#matplotlib.axes.Axes.stackplot

I found labels & colors to be unclear because Length N list of str & Length N list of color made me think that Length have to be equal to length of x. It is better that length of labels & colors is equal to data series length (M).

Suggested Improvement

labels: list
A sequence of strings providing the labels for each data series.

colors: list, default: None
A list or tuple of colors. These will be cycled through and used to colour the stacked areas.

Matplotlib version

• Operating system: Windows 10
• Matplotlib version: 3.4.1
• Matplotlib documentation version (is listed under the logo): 3.4.1