The Xfce Evolution theme attempts to rid the Xfce desktop of visual distractions by providing a more consistent look (buttons, scrollbars, menus, etc) across older and newer applications.
If you like this theme please rate it so that other people can find it more easily.
Based on Ambiance:gtk2, Adwaita:gtk3, and Greybird:xfwm.
Blends well with 'elementary Xfce darkER' icon set and 'Noto Sans 9' fonts (see the INSTALL file in package).
Developed and tested on Xubuntu 17.04.