Created attachment 785797 [details]
YaST2 Control Center Icons
Sorry for my late response, I was busy and I didn't see the notification email.
This issue was raised for Leap 15.0 but it also happens in Tumbleweed 20181002.
I was referring to the YaST2's Control Center icons, as Michalski mentioned
when using Plasma's Breeze/Breeze Dark theme uses oxygen icons instead of
hicolor ones.
Now, as a second workaround I symlinked every yast2 icon from
/usr/share/icons/hicolor/ to /root/.local/share/icons/oxygen/. After doing this
and removing the icon-cache.kcache file I can see the correct icons in YaST2's
Control Center.
I'm attaching the before and after screenshots.