如何从大列表中选择要在颜色栏中显示的特定颜色数量？- Matplotlib

import matplotlib.pyplot as plt
import numpy as np

colors = ['red', 'green', 'blue', 'yellow', 'orange', 'purple', 'pink', 'brown']

num_colors = 3
selected_colors = colors[:num_colors]

x = np.arange(10)
y = np.sin(x)

plt.scatter(x, y, c=selected_colors)
plt.colorbar()
plt.show()