When using new themes other than the built-in ones, I always found that when Caja is displayed in dual pane, and when I select an item in the first pane then select new item in second pane, the first selected item in the first pane has white font color.
Check this post:
The way I get round these kinds of problems is by installing several themes between all of which I know all of the elements I want will be included one way or another. Then, I set it up with a specific theme where I know most of the elements will be right, but where there may be one or two things that are not right. Then, I go into the "customise" tab and pick out elements of other themes to mix and match with the main theme I am using.
So, for example, the theme combination I am using right now is:
controls: numix
window border: ambient red
icons: mate-faenza-dark
pointer: DMZ-white
So, the two themes I have installed there, are Numix and Ambient Red
Numix is in the repos
I got Ambient Red from the "Mate Look" website
Didn't work for me, I installed that gtk inspector from libgtk-3-dev package but I can't launch it or use it.
I don't know why GtkInspector is not working for you. I just did that and worked for me.
I use Numix and had the same issue until I create the file gtk.css with the following content:
.caja-notebook .view:not(:focus)
{
color:rgb(54,54,54);
}
and save it in ~/.config/gtk-3.0 and reboot.
This set a dark gray text color in the panel that is out of focus. Change it as you like.
Thanks really for the steps, in fact I work a lot with dual pane in Caja and your modification really helps a lot.