XnView Software

How about adding a TreeFontHiColor2 option? So both active and inactive pane text color can be seen?

It's not necessarily needed, because it's depend of your Windows appearance setting.
For me only one option is enough (and works for both cases), but why not 2 colors ? ...
in the ini file :
[Browser]
TreeFontHiColor=14401321

in your case ghost zero, using dark gray instead white should works, without changing windows settings....

if its not too difficult to add, i would prefer having 2 options. i prefer the highlight text be white and the inactive text be black.

any progress yet?