Yast gui does not use system colors

I use openSUSE in a low light environment, and have configured KDE for a soft green text on dark background. It is easy on the eyes. When I start Yast it is like pointing a bright light into my (dark adjusted) eyes. Ouch! I tried using Yast -> system -> /etc/sysconfig-editor -> System -> Yast2 -> GUI ->
Y2NCURSES_COLOR_THEME
inverted
but this is apparently only for ncurses, and not qt or gtk.

All the applications inherit the system colors - except Yast. Why can’t Yast gui use the system color settings?

I am using openSUSE 13.1 64-bit intel.

The Qt version of YaST uses themes and the standard theme uses its own colors. You could switch from yast2-theme-openSUSE-Oxygen to yast2-theme-openSUSE-Crystal and YaST should use the system’s colors instead. (just install the latter package)

Or turn off theming completely by setting the environment variable $Y2STYLE to an empty value.
To do this globally, add the following line to /etc/environment, f.e.:

Y2STYLE=

But note that YaST runs as root, so it uses root’s color settings.
Change them with systemsettings run as root:

kdesu systemsettings

Or you could also create another theme, see here f.e.:
http://lizards.opensuse.org/2008/12/23/yast-qt4-stylesheet-editor/