Unfocused Tab Color Selector for Stacked Windows

[abstractionmage]

With the introduction of an Active Hint Color Selector (#462) the color and opacity of the focussed window's border, as well as its tab in a stack of windows, can be freely chosen. However, the default background color and opacity of unfocused tabs in a stack cannot currently be changed, it will always remain fully opaque Zorba (#9B8E8A). This color looks good in combination with the default Active Hint Color, but once I changed my Active Hint Color to Cornflower Blue (#7E68F7) and set its opacity to 42% in order to let my wallpaper shine through, the inactive tabs looked really out of place:

For better desktop customization I would appreciate a second color selector which changes the background color and opacity of unfocused tabs in stacks of windows.