Horizontal Colored Bands Light

import matplotlib.pyplot as plt
import numpy as np
from scipy.cluster.hierarchy import dendrogram, linkage, fcluster, set_link_color_palette
from matplotlib.patches import Rectangle

np.random.seed(654)

labels = ['Item_' + str(i) for i in range(1, 13)]
data = np.random.rand(len(labels), 4) * 50
Z = linkage(data, method='average')

fig, ax = plt.subplots(figsize=(12, 9), facecolor='#ffffff')
ax.set_facecolor('#ffffff')

set_link_color_palette(['#27D3F5', '#F5276C', '#6CF527', '#F5B027'])

dn = dendrogram(Z, labels=labels, orientation='right', leaf_font_size=11,
                color_threshold=0.55*max(Z[:,2]), above_threshold_color='#9ca3af', ax=ax)

# Colored bands for clusters
clusters = fcluster(Z, t=3, criterion='maxclust')
band_colors = ['#F5276C15', '#27D3F515', '#6CF52715']

for i, leaf in enumerate(dn['leaves']):
    c = clusters[leaf]
    rect = Rectangle((0, i*10 - 5), max(Z[:,2]), 10,
                     facecolor=band_colors[(c-1) % len(band_colors)], edgecolor='none', zorder=0)
    ax.add_patch(rect)

ax.set_title('Horizontal Cluster Analysis', fontsize=15, 
             color='#1f2937', fontweight='bold', pad=15)
ax.set_xlabel('Distance', fontsize=11, color='#374151')
ax.set_ylabel('Items', fontsize=11, color='#374151')
ax.tick_params(axis='both', colors='#374151', labelsize=10)
ax.spines['top'].set_visible(False)
ax.spines['right'].set_visible(False)
ax.spines['left'].set_color('#e5e7eb')
ax.spines['bottom'].set_color('#e5e7eb')

plt.tight_layout()
plt.show()