Bug summary

Perhaps this is an understood and accepted behaviour change, but I did not see anything in the changenotes. If we set the facecolor of a violin object after creating it, we now also override the default alpha.

Code for reproduction

import matplotlib.pyplot as plt
import numpy as np

fig, ax = plt.subplots()

data = np.random.normal(size=(10, 3))
violins = ax.violinplot(data)

first_violin = violins['bodies'][0]
first_violin.set_facecolor('tab:red')

plt.show()

Actual outcome

With main I get

Expected outcome

With 3.10 I get

Additional information

Bisects to #27304. The default alpha is now included in the default facecolor as a (color, alpha) tuple, rather than being passed by the alpha parameter.

Operating system

Ubuntu

Matplotlib Version

main

Matplotlib Backend

qtagg

Python version

3.13.7

Jupyter version

No response

Installation

git checkout