How do I only skin the explorer background and nothing else?

You will have to use Skin Studio, very easy. This is for the right side. Open the WB in SKS (skinstudio) Now click on Backgrounds it will say Edit Explorer backgrounds bitmaps. At the top it will say Explorer Backgrounds open that. The active window is what you see when Explorer is open The in-active is what shows when you click on it's taskbar button to open it or minimize it it. I use a 1 pixel wide by 3000 pixel long graphic. You can use about any size actually even a 10x10 pixel image. Make it the color you wish. You will see a couple buttons one says Edit Image and a little one next to it, click on the little one and click import. Now just find your image and import it there. Click apply skin. You may have to close Explorer and open it again to see the change.

If you want to change the left side color go to. Edit Explorer/IE Shell Parts. Than go down to Edit Explorer Parts and click on it. Look for Folders bar and click on that. At the bottom of this window you will see Extra Settings, click on that. There you can from the drop down menu on the bottom right change it to any color listed or make your own color using the Color Section.

If it works like it does in Windows 7. open WB config and select the default Windows skin.

Click on the Background button.

Click on Explorer Backgrounds.

Pick a background and click on Apply Style. You should now have the default Windows theme with the explorer background of your choosing.

Have a nice day.

 P.S.. There are thousands of Win 8.1 users who have  no trouble running WindowBlinds  on that OS. Perhaps you have given up too soon.  What sort of trouble are you having and did you submit a ticket to support?

Well tells one how much I use WB to change things. lol. If someone wants to change just the color at least they will know how to do that. Also changing the Explorer background doesn't change the left side color as I explained. So now there are two options.