Previously while on Xubuntu 14.04 I had developed a customized theme. Please if interested in that refer here: http://www.lueckdatasystems.com/Custom_assembled_attractive_dark_blue_th...

Since LTS upgrading to Xubuntu 16.04, I had to adjust it slightly to obtain satisfactory results. Here is what I came up with.

1) First set the window style and icons as follows:

Click the button labeled "All Settings" to go back to the main Settings Manager

2) Next set the window manager as follows:

Click the button labeled "All Settings" to go back to the main Settings Manager

3) tweak the highlight color as follows:

Settings Manager \ Theme Configuration

4) Finally, edit the ~/.gtkrc-2.0 configuration file:

Shown below is a preview of how it turned out:

I like the fact that with these settings I still get the traditional scroll bars... grey sliders with arrows at each end.