# https://stackoverflow.com/questions/59231945/how-to-set-histogram-color-as-a-gradient

def pretty_hist(data, bins, n_loops=8, alpha=1, base_color=[0.121569, 0.466667, 0.705882]): 
    N, bins, patches = plt.hist(data, bins=bins, density=True)
    bm = bins.max()
    bins_norm = bins / bm
    bc = base_color

    for bin_norm, patch in zip(bins_norm, patches):
        grad = np.sin(np.pi * n_loops * bin_norm) / 15 + .04 
        color = (bc[0] + grad, bc[1] + grad, bc[2] + grad, alpha)
        patch.set_facecolor(color)

    plt.gcf().set_size_inches(6, 1)
    plt.box(None)
    plt.show()
   
  
import numpy as np
import matplotlib.pyplot as plt

np.random.seed(2)
x = 0.06*(np.random.uniform(-1, 1, 8000) + 0.05*np.random.randn(8000))

pretty_hist(x, 400, n_loops=8,  alpha=0.9)
pretty_hist(x, 400, n_loops=16, alpha=1)