I'm with alex on this, lawrence. All Justin can do is program elements like the routing matrix to use colors specified in the theme. It's up to the theme creator to choose their colors carefully.
With a bit of experimentation, i've discovered that the routing matrix uses the Main Window Background for it's background (not surprising) and the Main Window Text color for it's text (again, not surprising).
If there's enough contrast in the main window for readability, the routing matrix should be ok too.
If there isn't enough contrast in the routing matrix, the problem more than likely exists in the main window as well.
EDIT: Wait a sec.. something's not right here. Your pic shows 3 colors (black, white, grey). On my system, i only see 2 colors (matching my theme).
hmmmmmmm.... ok, so i have no idea what i'm talking about. Do you see the problem on the default theme?
teej