Pastel Zone Bands Light

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

np.random.seed(456)

labels = ['Sample_' + chr(65+i) for i in range(14)]
data = np.random.rand(len(labels), 4) * 80
Z = linkage(data, method='ward')

fig, ax = plt.subplots(figsize=(14, 8), facecolor='#ffffff')
ax.set_facecolor('#ffffff')

# Pastel horizontal bands
zone_colors = ['#F5276C15', '#27D3F515', '#6CF52715', '#F5B02715']
max_dist = max(Z[:,2])
for i, color in enumerate(zone_colors):
    ax.axhspan(i*max_dist/4, (i+1)*max_dist/4, color=color, zorder=0)

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

dn = dendrogram(Z, labels=labels, leaf_rotation=45, leaf_font_size=11,
                color_threshold=0.55*max(Z[:,2]), above_threshold_color='#9ca3af', ax=ax)

ax.set_title('Hierarchical Clustering with Distance Zones', fontsize=15, 
             color='#1f2937', fontweight='bold', pad=20)
ax.set_xlabel('Samples', fontsize=11, color='#374151')
ax.set_ylabel('Ward Distance', 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')

# Zone labels
for i, label in enumerate(['Low', 'Medium', 'High', 'Very High']):
    ax.text(-2, (i+0.5)*max_dist/4, label, color='#6b7280', fontsize=8, va='center', ha='right')

plt.tight_layout()
plt.show()