Inconsistent outline color of panels
I don't know if it is intentional, but it is really bad looking in my opinion. All system pup-ups/panels have darker outline than body (right top menu, notification panel etc.) except dash and workspaces panel. Even search bar has darker background so readability is not a reason for this. Maybe both of these elements need more general redesign, because they are a bit problematic in different fields for exampple: dash has really small icons sometimes, workspaces panel is stretched even when there are only two workspaces etc. (that is for different issue I guess). Darker background looks more modern and consistent with other elements like buttons etc. Please consider changing that outline color.
elements with darker outline:
elements with lighter outline: