found the solution !
If you work in the dark, like myself, here is what you do.
2. Go to www.xfce-look.org
and download yourself pOSv1 , and Ambiance Dark Red
3. open a file manager where both files are visible
4. Drag them into an open "Settings->Appearance" dialog.
5. Set Ambiance Dark Red there, then close the dialog
6. Go to "Settings-> Window Manager" and select pOSv1
Test regular apps, like Xfce Terminal, it should be nice and dark (if you don't like the Menu letters all shrunk together, then select Adwaita (dark version) in Appearance).
Now !! the secret to get the QT-BASED apps (Kate, Konsole) also dark.
yum install qt5-qtstyleplugins qtcurve-qt5 qt5ct
cp /etc/xdg/xfce4/xinitrc ~/.config/xfce4/xinitrc
add this at the top:
Now , log out, and log back into your Xfce
open a terminal, and execute: qt5ct
you should see this here:
Now change your style to "gtk2" , you will see that it changes to dark. Click on OK, or Apply and then OK
Now, test Kate, and Konsole
HA LE LUYAH !