Visual Studio 2019 Color Theme Editor - How to make background color of Solution Explorer transparent?

Question

Goal: I'm using a VS extension called "ClaudiaIDE" that enables you to set an image as a background to Visual Studio 2019. I set the background to a wood grain wallpaper (it looks amazing). It makes the code editor background and main window background transparent so you can see the image, but not anything else. I then started using Color Theme Editor to add transparency to other sections of the VS IDE so it's mostly showing the background image. I want the right side windows (like solution explorer) to be transparent as well.

1. Two stackoverflow answers say the color value is stored under "treeview". I changed the "treeview" background using the wizard but it made no difference (despite other SO comments saying it worked). Likely due to the old answers being for VS 2017 or earlier.
2. I then changed the "treeview" color manually in the CustomTheme.vstheme file and I successfully made the grey color transparent, but now there is an absolute black blackground, which was perhaps there to give a shadow effect. The code I edited is below (The opacity is intentional):

<Category Name="TreeView" GUID="{92ecf08e-8b13-4cf4-99e9-ae2692382185}">
      <Color Name="Background">
        <Background Type="CT_RAW" Source="00252526" />
        <Foreground Type="CT_RAW" Source="FFF1F1F1" />
      </Color>

3. I searched for every reference of "#FF000000" and for testing made them all fully transparent: "#00000000". This made no difference, solution explorer retained its "#FF000000" (by observation only, I don't know where the code is). I know the hex is right because I copied a screenshot into paint.net and grabbed the color.

4. I then changed my Microsoft Windows settings so that it didn't use the dark background, in case it was applying that to the VS windows. No change.

If anyone has any ideas on how to access the black underlying background for windows like "solution explorer" i would greatly appreciate it. It must be getting that value from somewhere.

Answer 1

Install this:
https://marketplace.visualstudio.com/items?itemName=VisualStudioPlatformTeam.VisualStudio2019ColorThemeEditor
Top menu:
Tool=>Customize Colors => choose theme
Show All Elements button (same row with save icon)

Search for (there is search box):
Environment → ToolWindowFloatingFrameInactive
Environment → ToolWindowFloatingFrame
Tool Window → Tab → Background
TreeView → Background