[Suggestion][UI] More emphasis needed on Custom Meta-Data + and - buttons?

In Project > Project Settings > Custom Meta-Data, the “+” and “-” buttons should be boxed/outlined or somehow emphasized in some other way, so as to be more obvious that are available for use. They currently seem easy to overlook.

Scrivener 2.9.0.1 beta (19429) 20 Nov 2017
Windows 10 Pro 64 bit 10.0.15063

Appears that the buttons are just as faded/grayed in Scrivener 3 for Mac OS X, so presumably should disregard this. A bit too faded/grayed out/low contrast/overlookable for my taste, but I’ll adapt.