Multi-Color Boxplot

import matplotlib.pyplot as plt
import numpy as np

COLORS = {'c1': '#6366F1', 'c2': '#10B981', 'c3': '#F59E0B', 'c4': '#EF4444', 'median': '#FFFFFF', 'background': '#FFFFFF', 'text': '#1E293B', 'text_muted': '#64748B', 'grid': '#F1F5F9'}

np.random.seed(42)
data = [np.random.normal(m, 10, 80) for m in [45, 55, 50, 60]]
colors = [COLORS['c1'], COLORS['c2'], COLORS['c3'], COLORS['c4']]

fig, ax = plt.subplots(figsize=(10, 6), dpi=100)
ax.set_facecolor(COLORS['background'])
fig.patch.set_facecolor(COLORS['background'])

bp = ax.boxplot(data, widths=0.5, patch_artist=True, showfliers=False,
                medianprops=dict(color=COLORS['median'], linewidth=2))

for patch, color in zip(bp['boxes'], colors):
    patch.set_facecolor(color)
    patch.set_edgecolor('white')
for whisker, cap, color in zip(bp['whiskers'][::2], bp['caps'][::2], colors):
    whisker.set_color(color)
    cap.set_color(color)
for whisker, cap, color in zip(bp['whiskers'][1::2], bp['caps'][1::2], colors):
    whisker.set_color(color)
    cap.set_color(color)

ax.set_xticklabels(['Product A', 'Product B', 'Product C', 'Product D'])
ax.spines['top'].set_visible(False)
ax.spines['right'].set_visible(False)
ax.spines['left'].set_color(COLORS['grid'])
ax.spines['bottom'].set_color(COLORS['grid'])
ax.yaxis.grid(True, color=COLORS['grid'], linewidth=1, zorder=0)
ax.set_axisbelow(True)
ax.tick_params(axis='both', colors=COLORS['text_muted'], labelsize=9, length=0, pad=8)
ax.set_ylabel('Sales', fontsize=10, color=COLORS['text'], labelpad=10)

plt.tight_layout()
plt.show()