import numpy as np
import matplotlib.pyplot as plt
from matplotlib.colors import LinearSegmentedColormap


def color_grid(xx, classes):
    x = xx.ravel()
    Z = np.zeros(x.shape)
    dx = (x.max() - x.min())/classes
    for i in range(classes):
        Z[(i * dx <= x) & ((i + 1) * dx >= x)] = i
    return Z.reshape(xx.shape)


colors = ['b',
          'r',
          'm',
          'c',
          'g',
          'xkcd:orange',
          'xkcd:peach',
          'xkcd:bright pink',
          'xkcd:crimson']


xx, yy = np.meshgrid(np.arange(0, 10, 0.02), np.arange(0, 10, 0.02))
fig, sub = plt.subplots(len(colors)-1, 1)

for i, ax in enumerate(sub.flatten()):
    cm = LinearSegmentedColormap.from_list('foo', colors[0:i+2], i+2)
    Z = color_grid(xx, i+2)
    ax.contourf(xx, yy, Z, cmap=cm)
plt.show()