I have used the following code:

import numpy as np
import matplotlib.pyplot as plt
def f(x, y):
    return ( ((np.log(x**2) / np.log(y**3)) / x**2 )*500)

x = np.linspace(0, 600, 4)
y = np.linspace(0, 1000, 4)

X, Y = np.meshgrid(x, y)
Z = f(X,Y)

fig = plt.figure()
ax = plt.axes(projection='3d')
ax.contour3D(X, Y, Z, 50, cmap='binary')
ax.set_xlabel('x')
ax.set_ylabel('y')
ax.set_zlabel('z')

to create the following 3D plot:

How can I color the 3D plot in "purple" and add a drape over it?