I had a similar problem, italics and reverse video was switched.
"Screen's terminfo description lacks italics mode and has standout mode in its
place, but using the same escape sequence that urxvt uses for italics. This
means applications (like vim) looking for italics will not find it and might
turn to reverse in its place, while applications (like less) asking for
standout will end up with italics instead of reverse. To make applications
aware that tmux supports italics and to use a proper escape sequence for
standout, you'll need to create a new terminfo file with modified sgr, smso,
rmso, sitm and ritm entries:
$ mkdir $HOME/.terminfo/
$ infocmp "$screen_terminfo" | sed \
-e 's/^screen[^|]*|[^,]*,/screen-it|screen with italics support,/' \
-e 's/%?%p1%t;3%/%?%p1%t;7%/' \
-e 's/smso=[^,]*,/smso=\\E[7m,/' \
-e 's/rmso=[^,]*,/rmso=\\E[27m,/' \
-e '$s/$/ sitm=\\E[3m, ritm=\\E[23m,/' > /tmp/screen.terminfo
$ tic /tmp/screen.terminfo
And tell tmux to use it in ~/.tmux.conf:
set -g default-terminal "screen-it"
If your terminal supports 256 colors, use:
instead of "screen". See the FAQ entry about 256 colors support for more info.
Also note that tmux will still display reverse video on terminals that do not
end of this FAQ