Step 1: Make a background image
You need an image file which is exactly 3840×1080. The reason you need one that size is because the image needs to stretch across two front of room displays. Even if you only use one display, it has to be that size. In single display rooms, you will always see the right side of the image. In dual display rooms you will see all of it.
Save your image as wallpaper.jpg. If you want to use a different image file format or name, pay attention to the XML because I use this name in it. Just change the xml to contain your filename and extension.
Step 2 – Create an XML file
If you don’t know by now. MTR on Windows uses an XML file with parameters in it to make changes to the system. There’s a bunch of stuff you can do with the XML and the list is growing all the time. But for now, all I want to talk about is the XML settings which are specific to the wallpaper.
Open Notepad and add the following
<SkypeSettings>
<Theming>
<ThemeName>Custom</ThemeName>
<CustomThemeImageUrl>wallpaper.jpg</CustomThemeImageUrl>
<CustomThemeColor>
<RedComponent>1</RedComponent>
<GreenComponent>120</GreenComponent>
<BlueComponent>199</BlueComponent>
</CustomThemeColor>
</Theming>
</SkypeSettings>
I highlighted the word wallpaper.jpg because as I said above, you can save the image file as whatever you want. But it has to match the xml.
Save the file as SkypeSettings.xml
Step 3 – Copy the image file and xml to the MTR
You need to save both files to
C:\Users\Skype\AppData\Local\Packages\Microsoft.SkypeRoomSystem_8wekyb3d8bbwe\LocalState
You can do this however you want. If you connect to the MTR PC remotely, go to settings and log in as admin, browse to the folder and paste them there.
If you want to use remote command line or file explorer, go for it. Just keep in mind you might get a permissions block navigating past AppData.
Either way, just copy the files there.
Step 4 – Restart the MTR PC
The XML only gets processed by the MTR after a restart. Once you have restarted, the new wallpaper will be on your front of room display(s).