How to decouple hatch and edge color in matplotlib?

I would like to draw a bar in matplotlib with white as fill color, red as hatch color and black as edge color. However, it looks like the edge color changes also the color of hatch. So, I am not able to decouple the color of edges and hatch. Do you have any suggestion? Thanks.

Plot bar plot twice:

import matplotlib.pyplot as plt
from matplotlib.patches import Ellipse, Polygon

fig = plt.figure()
ax1 = fig.add_subplot(111)
# draw hatch
ax1.bar(range(1, 5), range(1, 5), color='none', edgecolor='red', hatch="/", lw=1., zorder = 0)
# draw edge
ax1.bar(range(1, 5), range(1, 5), color='none', edgecolor='k', zorder=1, lw=2.)

ax1.set_xticks([1.5, 2.5, 3.5, 4.5])
plt.show()