Dockbar marks the active application by color, but not the active window

For applications with several main windows open (firefox, libreoffice, atril, terminal), the icon in the dockbar is marked "active" if one of these windows is the top window.

However, in the window list or in the previews shown the only indication which window list entry or which preview corresponds to the currently active window is the window title in bold font (which is hard to see especially if the font is small) There is no color or bar or whatsoever.

Could we please have a more obvious visual indication? I think a different background color for this window list entry (or for the frame around this preview) would be helpful.