Trying to get Firefox scrollbar color to match Gnome GTK4 color

I’m using the userContent.css file in Firefox’s chrome folder to edit the scrollbar and i’m trying to make it look like Gnomes scrollbar, with a grey scrollbar and once selected it goes a bit lighter great with a transparent scrollbar track. I’ve got the transparent part in Firefox, but I can’t quite get the colors right to look like Gnome in GTK4. Firefox can use the GTK3 system default colors for the scrollbar, but it selects to blue when you click the scrollbar and I’d rather that looked like Gnomes GTK4 with a light grey onces selected and dragged.

Any ideas would be most appreciated.

This is what I want Firefox scrollbar to look like, but after this image is how it currently looks when dragged/clicked:

You can check what scripts Add Water is using (maybe it adresses your request as well), or just use the package as it is, if it suits you.