Outline buttons are showing inverted colors in active mode

[puehringer]

This PR (#616) adjusted the outline buttons to not "invert" its color. The problem is that the font-color needs to be de-inverted as well.

The problem can be seen when adding the active class to a button, or when click and holding a button (:active):

<button type="submit" class="btn btn-outline-secondary btn-sm active">Save</button>

Could you take a look at it @dvdanielamoitzi? If you need anything, let me know.

[puehringer]

@dvdanielamoitzi It also shows up like this in our permission dialogs:

I think we should prioritize this higher, can you take a look at it or should I?