Default theme

I found this thread on restoring to the default themes, but it doesn't seem to affect anything.

I'm specifically trying to remove this theme


That looks like a lot more than just a theme. It includes scripts, toolbars and registry changes if you went through with all of it.

Which things do you need help undoing?

Just the colors, all I had done was select theme in the opus settings

The first page you linked explains how to reset the colors, via Preferences > Display > Colors & Fonts.