Unable to alter properties of right axis labels

In the following code I attempt to plot right and left yaxis labels each with its own color. The left axis comes out OK - red, medium
The right axis comes out the default.
I have tried everything I could think of (admittedly not much) to alter any property of the right labels and have had no success -
How do I alter the right axis label properties in the example below???
thanks for any help.

Jim

This is taken from the 'two_scales.py' in the examples directory.

from matplotlib.matlab import *

ax1 = subplot(111)
t = arange(0.0, 10.0, 0.01)
s1 = exp(t)
plot(t, s1, 'b-')
ax1.yaxis.tick_left()
for label in ax1.get_yticklabels():
     label.set_fontsize('medium')
     label.set_color('r')

# turn off the 2nd axes rectangle with frameon kwarg
ax2 = subplot(111, frameon=False)
s2 = sin(2*pi*t)
plot(t, s2, 'r.')
ax2.yaxis.tick_right()
for label in ax1.get_yticklabels():
     label.set_fontsize('medium')
     label.set_color('b')

xlabel('time (s)')