Text in chat that has dark colors, also has black drop shadow, which makes the text completely unreadable. Dark colors (especially black and darkblue), should have a lighter drop shadow color that contrasts with the text, since the purpose of a drop shadow is to allow text to be read against any background.

What it looks like currently:

What I'm requesting (you'll need to play with it to find a saturation that works best in all scenarios):

If this were an option that were off by default, that would also be okay IMO.