When I first installed ktorrent and keepassx on my laptop, the font seems to be very small, I tried to figure out where to change the font but seems unable to find any solid solution except this -
However once I have changed the font type and size using kcontrol, the changes only applied to ktorrent, keepassx is still using very small font that hurts my eyes. Since most of the kde based apps are written using qt toolkit, I decided to run qt and tab to see if any application are available to change qt setting, I found there is qtconfig and decided to run it -
In fact qtconfig is the gui configuration for qt, I tried to change the font type and size again this time. And running keepassx again, the font has changed based on the configuration I applied. I'm not kde user but since I have used some of kde based applications, I think this is good trick to share. For users who want to change their GTK applications attributes, you can try out gtk-chtheme.