BUG: set_tick_params labelcolor should apply to offset

[astrofrog]

The following example:

import matplotlib.pyplot as plt

fig = plt.figure()
ax = fig.add_subplot(1,1,1)
ax.plot([1.01e9,1.02e9,1.03e9])
ax.yaxis.set_tick_params(labelcolor='red')
fig.savefig('test.png')

produces the following output:

The offset label should likely be set by the labelcolor option too.

[jenshnielsen]

Fixed on master by #6445 but this has not been backported

[QuLogic]

Fix is now backported.