The dark breeze theme works great only for KDE apps, but for other qt and gtk2/3 apps it's inconsistent :
https://imgur.com/tRLjDhx
https://imgur.com/dcc3CSh
https://imgur.com/gafFvke
https://imgur.com/di5fxcn
The white on blue background is really hard to read ! with black foreground while selecting or mouse hovering it will be great !
Or the light blue should be little dark to be able to read white text.

I'd recommend bringing these up on phabricator. There's been quite a bit of activity around improving various aspects of the breeze theme in recent months, so now is probably a good time to get the suggestions incorporated and fixed.