CODE EXAMPLE FOR PYTHON

seaborn boxplot change filling

import matplotlib.pyplot as plt
import seaborn as sns

fig,(ax1,ax2) = plt.subplots(2)

sns.set_style("whitegrid")
tips = sns.load_dataset("tips")

sns.boxplot(x="day", y="total_bill", hue="smoker", data=tips, palette="Set1", ax=ax1)
sns.boxplot(x="day", y="total_bill", hue="smoker", data=tips, palette="Set1", ax=ax2)

for i,artist in enumerate(ax2.artists):
    # Set the linecolor on the artist to the facecolor, and set the facecolor to None
    col = artist.get_facecolor()
    artist.set_edgecolor(col)
    artist.set_facecolor('None')

    # Each box has 6 associated Line2D objects (to make the whiskers, fliers, etc.)
    # Loop over them here, and use the same colour as above
    for j in range(i*6,i*6+6):
        line = ax2.lines[j]
        line.set_color(col)
        line.set_mfc(col)
        line.set_mec(col)

# Also fix the legend
for legpatch in ax2.get_legend().get_patches():
    col = legpatch.get_facecolor()
    legpatch.set_edgecolor(col)
    legpatch.set_facecolor('None')

plt.show()