Created attachment 65718 [details]
screenshot of windows classic theme
This is more of a stylistic preference than a bug per se.
When using the Aero theme, Libreoffice applies a very light (almost imperceptible unless it's the highlighted row or column) shading to the right side of row headers and bottom of column header.
When the user switches to the Windows classic theme, the shading becomes incredibly pronounced and (in my opinion) pretty ugly.
Created attachment 65719 [details]
screenshot of windows aero theme
This is not our bug, it's how Windows classic theme deals with colors. Nothing in the LibreOffice code is saying "if you run Windows Classic Theme make your color look like XYZ"
:) Marking as NOTOURBUG
Just for my side two cents, I actually like it more pronounced so it must be a personal taste thing