Change Colour of Dropdown Slicer Outline - Power B...

Currently when using dropdown slicers, there is no way of formatting the outline of the dropdown box itself (before you have interacted with it). It, by default, is a dark grey colour which cannot be changed. This makes it incredibly hard to get it to stand out on a dark background dashboard.

This should be a very easy feature to add, and has been requested for years with no progress...