Hey, thanks for the useful shard!

I am having an issue where markterm is making some text black, which is invisible on my black terminal background.

I looked at terminal.cr, and it looks like it's selecting light mode because my $COLORFGBG is set to 15;0. However, if the FG is 15 and the BG is 0, shouldn't that mean the font is white on black, in which case markterm should return false from terminal_light?

I could be reading that wrong as well - lmk if I missed something.