Created attachment 78260 [details]
Helium Plasma Theme, notice how krunner doesn't fit
Krunner is, due to high transparency, not usuable in some of the plasma themes (e.g. Air for netbooks).
When trying to apply a different plasma theme to Krunner via:
System Settings -> Desktop Theme - Details: "Run Command Dialog" (which is also a misleading name), nothing happens.
In the KDE Forum (see URL above) on mentioned that Krunner overtakes the plasma theme which is applied to the panels. However, this also fails (see attached screen shots).
Maybe this commit is related to this:
*** This bug has been marked as a duplicate of bug 306273 ***