Board Thread:General Discussion/@comment-5377726-20171105050923/@comment-5454372-20171108085705

Your Wikia.css doesn't contain the scrollbar code, so what you need to change is still back over in Common.css.

Go all the way to the bottom to the  block, and then remove this line that's inside it:

background-image: -webkit-gradient(linear, 0 0, 0 100%, color-stop(0.5, rgba(255, 255, 255, 0.2)), color-stop(0.5, transparent), to(transparent));

That seems to be what's causing two colours to show up on the scrollbar thumb.