0.87.7: Ticks are always black

I have a very customized matplotlibrc for rendering charts for web
pages. The biggest change is that I render everything white on black
by default. This has worked fine up through 0.87.5 (the last release I
grabbed) but in 0.87.7, the ticks on the axes are black (the axes
color is white). Am I missing a setting somewhere or is this a bug?