I know I can change PowerShell console colors by setting in my profile something like:
$Host.UI.RawUI.BackgroundColor = \"White\" Clear-Host
As far as I know, you can't. The console API doesn't support custom color. If you do this:
$x = (Get-Host).UI.RawUI $x | gm
you'll see that BackgroundColor is of type System.ConsoleColor.