Changing the background color of the axes planes of a 3D plot

Using the same example. You can set the pane color using the set_pane_color method as described here http://matplotlib.org/mpl_toolkits/mplot3d/api.html#axis3d. You can set the color using the RGBA tuple:

# scatter3d_demo.py
# ...
# Set the background color of the pane YZ
ax.w_xaxis.set_pane_color((1.0, 1.0, 1.0, 1.0))
plt.show()