Scrollbar Width and Color

Periodically I scroll through the channel Member List on a Server. When I do this in Dark Mode theme I don't see the scroll bar on the right side of the Member List. It appears to be there. I see it when using the Light Mode theme. However, it is very thin. When using the Dark Mode theme, the color/shade of the scroll bar is darn near the same as the Member List making it almost impossible to see.  Its width is such that it is difficult, almost impossible to grab with my mouse before the expand window function is activated.

This is very frustrating for me.

Is there a way to enlarge the scroll bar and perhaps change its color when in Dark Mode?