The font color and outlines (as well as some other things) can indeed be changed in the in-game phone, as mentioned by the tutorial at the beginning.
I'll reverse the default font color and outlines to white with a black border, though. That was intended to be the default anyway, but apparently something went wrong with that. So, thanks for letting me know.
Edit: I just checked and it was even worse than I had expected. The gray color wasn't even intended to be available as a choice at all. It's crazy that no one has mentioned it thus far, because it's been like that for way longer than I want to admit without me knowing about it.
So, again, thank you for letting me know. This needed to be fixed real bad.