I know how to retrieve the wallpaper from the registry:
HKEY_CURRENT_USER\Control Panel\Desktop\Wallpaper
But what if the user chooses to use a solid color as a wallpaper, how do I retrieve that specific color?
You can retrieve it from
HKEY_CURRENT_USER\Control Panel\Colors\Background
It is a string containing a space-seperated tuple "R G B", e.g. "255 0 0" for red, "255 102 0" for orange.
See here for information on acquiring the registry value using C#, C++, F#, and VB.NET.
And the example below for Powershell
# PowerShell Registry Key example
$Registry_Key = "HCU:\Control Panel\Colors\"
Get-ItemProperty -path $Registry_Key -name Background