You don't understand what I said, and you don't seem to know much about Windows. Previously it worked like this;

1. Apply skin, skin changes desktop color.

2. If you want to then change the desktop color back to what it was, (I prefer black),

  a. Right click on desktop

  b. Click on Personalization

  c. Click on Window Color

  d. Click on Advancedd Appearance Settings

  e. Select desired color from drop-down next to Desktop

  f. Click apply

  g. The desktop freezes and a Please Wait message pops up.

  h. The selected color is then applied.

Now with WB8, after 2g, the selected color is not applied. An additional step is required, logging out and logging back in, only then is the selected color applied.

With wallpapers smaller than full screen the desktop is partially exposed. Oftentimes the background color applied by a skin does not match the wallpaper. Oftentimes a black background best sets off the wallpaper. So it's not unusual to want to choose your own desktop color and previously that was not particularly difficult. It is much more troublesome now because logging off and on may mean having to close and re-open any number of programs, files, etc.

I would say 99.9 % of WindowBlinds users have the color applied by WB's so what you are doing is a bit unusual. Screenshots would help.

OK, you mean the desktop color when your wallpaper isn't full screen. Wizard1956 figured it out as he and I have been working to help you with this. I would never use an undersized wall, so I didn't get your meaning at first.

It doesn't mean I don't know anything about Windows. It means I don't use non fitting walls. I gave up XP features when I gave up XP.

Just so we're clear;

Brightside windowblind with color applied by skin. 

Opening Window Color and Appearance app

Note I've selected black and the apply button is functional.

Apply button has been clicked and is now greyed out, but color has not changed. Previously at this point, it would.

But now after logging out and back in it has been applied.

I don't think I can make it any clearer.

I have walls in many sizes. This is a nice effect. Art by Vladimir Kush. I've just never heard of anybody always using full-size walls all the time. I use artwork, personal pictures, a lot of it doesn't look good if it's over-enlarged or distorted. I'm just kind of stunned that in a customization forum people wonder why you would want to change your desktop background color . Sticking with full size walls is a little limiting, there's a lot you can do with smaller walls and different background colors.

If you wish to change the desktop background colour permanently in a skin for your own satisfaction, see the answer in this thread: https://forums.wincustomize.com/445985/page/1/#3374146

I have people come into my shop thinking something is wrong with their computer if their wall is not covering the whole screen. not a lot but it does happen. lol

You would not believe the things people bring their computers in for.