As described here when using the dark themes and having lot of windows open it can be quite difficult to distinguish which one is focused.
As a workaround it may be a good idea to implement a function to color focused windows matching the default themes colors.
I have personally experimented this on Xfce by changing the colors of the xfwm4 elements with an image editor but I don't understand how to apply this to gtk managed windows (messing around with the css in vain).
Here is an example showing xfwm4 windows with the focused one having borders highlighted following the Mint-Y-Dark-Orange theme.
As described here when using the dark themes and having lot of windows open it can be quite difficult to distinguish which one is focused.
As a workaround it may be a good idea to implement a function to color focused windows matching the default themes colors. I have personally experimented this on Xfce by changing the colors of the xfwm4 elements with an image editor but I don't understand how to apply this to gtk managed windows (messing around with the css in vain).
Here is an example showing xfwm4 windows with the focused one having borders highlighted following the Mint-Y-Dark-Orange theme.