This extension allows you to pick a background image for the whole Visual Studio window.
Available on Visual Studio Gallery.
There are three color themes with transparence provided, so many parts of IDE can be transparent.
To customize the image, see Options->MoeIDE.
After installing the extension, go to Options->Environment->Color Theme, and select Light Transparent, Dark Transparent or Blue Transparent to apply the embedded theme.
To customize colors, see Color Theme Editor.
To debug a Visual Studio Extension, use C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\devenv.exe and /rootSuffix Exp in Debug page of project properties.