assign a color to a specific box in seaborn.boxplo

Question

I'm calling seaborn.boxplot roughly as follows:

   seaborn.boxplot(ax=ax1,
                    x="centrality", y="score", hue="model", data=data], 
                    palette=seaborn.color_palette("husl", len(models) +1),
                    showfliers=False, 
                    hue_order=order,
                    linewidth=1.5)

Is it possible to make one box stand out by giving it a specific color, while coloring all others with the given color palette?

Answer 1

The boxes made using sns.boxplot are really just matplotlib.patches.PathPatch objects. These are stored in ax.artists as a list.

So, we can select one box in particular by indexing ax.artists. Then, you can set the facecolor, edgecolor and linewidth, among many other properties.

For example (based on one of the examples here):

import seaborn as sns
import matplotlib.pyplot as plt

sns.set_style("whitegrid")
tips = sns.load_dataset("tips")
ax = sns.boxplot(x="day", y="total_bill", hue="smoker",
                 data=tips, palette="Set3")

# Select which box you want to change    
mybox = ax.artists[2]

# Change the appearance of that box
mybox.set_facecolor('red')
mybox.set_edgecolor('black')
mybox.set_linewidth(3)

plt.show()