Is there anyway to still keep darkcyan color for normal windows but remove thin separator line for properties windows? Some kind of tricky sizingmargin could do?
I tried several ways, modifying the image and also trying different margins and I could.get rid of that line and still keep that color under the address bar.

As for the rest of it.

White line, Edit the top and bottom of this image.
Explorer & Shell > Explorer > PreviewPane > <1> > <1>


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Toolbars, Headers and Rebar > Toolbars & Headers > List View Pop-up

Jerry