Onyx has by default "High Constrast" enabled. That is most notable on white text (on a dark background), but it does that to everything. You can turn that off or adjust it on a per-app basis. Mmm, I think that it's a long push on the app in the Onyx Launcher.
If you take the "nuclear option" you can disable a bunch of Onyx stuff by:
Code:
# pm disable com.onyx
But you have to be rooted.