Update for gnome 48

[LBY-L]

Just modify metadata.json:
{
"name": "Custom Accent Colors",
"description": "A GNOME Shell Extension that provides 7 Custom Accent Colors. The selected Accent Color can be applied to GTK4/GTK3 apps and the Gnome Shell.",
"uuid": "custom-accent-colors@demiskp",
"version": 11,
"shell-version": [
"48"
],
"url": "https://github.com/demiskp/custom-accent-colors"
}

You can't use the shell color theming, but there is the original gnome one and for gdm you can use the gdm settings app, all of the colors for flatpak/gtk3 apps work without problems, but the colors are not the same as the gnome shell ones, they are slightly less bright, so the developers should modify the colors to the new scheme