/usr/share/themes/Default-4.8/xfwm4/themerc is in xfwm4-themes 4.10.0-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | active_text_color=#ffffff
button_offset=5
button_spacing=0
full_width_title=false
maximized_offset=0
shadow_delta_height=4
shadow_delta_width=1
shadow_delta_x=1
shadow_delta_y=1
show_app_icon=true
title_horizontal_offset=4
title_shadow_active=frame
title_shadow_inactive=false
title_vertical_offset_active=2
title_vertical_offset_inactive=2
|