While recoloring chart text white for use on colored background I found no option to easily change axis label text color. Axis title, sure, but not the labels. The amazing Kacper Madej suggested adding style code to the Axis Labels Format field (did the trick), but it struck me as odd that it's a an easy to access option for every other component of a chart except the axis labels.
On a side note, Kacper Madej has been a huge help and deserves a promotion. Seriously, what a rad guy.