The preview pane in Win 7 and 8 has always been white, it is not skinnable. In Win 10 it does color though.
Just interesting why it was not fixed till now...
Hi Jim! Incredible! So there is my full settings step by step:
1. SkinStudio --> Change skin colors --> System colors --> Explorer background and Explorer folder bar background like on your screenshot!
2. SkinStudio --> Explorer parts --> Folders bar
2.a. Folders bar image --> *.bmp 8x8
2.b. Folders bar --> Extra settings --> Background Color --> The same color as the Explorer background in the System colors.
3. SkinStudio --> Background section --> Edit Explorer background bitmaps --> Active Window; Inactive Window; Active Window (Glass); Inactive Window (Glass) --> The *.bmp from Folders bar.
4. Go to your skin folder. Open *.uis (or *.sss) file of your skin and check the [Personality] section. Mine contains these four lines:
ExplorerBmp=Chronos 10\window_explorer.bmp <-- the same bitmap that I use in Folder Bar and Explorer background.
I don't remember does SkinStudio adds this line automatically or I've added it manually. However this line is present in the all skins I have on my PC.
I hope this help you...