OS was originally Ubuntu Mate 16.04 but I installed KDE plasma 5.8.8. Im having an issue in the Open Files window where all items appear to be selected and possibly the selection text color and background are set wrong. Possibly this issue is unique to chrome as its the only program that I have found to use this dialog. All others are using whichever one this is
I was facing the exact same problem, here is how I solved the problem.
Go to System settings -> Application Style -> GNOME Application Style (GTK)
"Select a GTK2 Themes" AND "Select a GTK3 Theme" both use "Breeze-Dark"
Problem solved! Apparently, there is a conflict between Ubuntu MATE (GTK2) and KDE (GTK3)