[Gambas-user] qt5 themes ?

[bb]

We have spent some hours here making our projects look especially
pretty using qt5ct.
This took some heavy hammer work to get QT5 project executables to
start with the correct ENV settings, mainly the QT_QPA_PLATFORMTHEME
setting, which under debian desktops does not "stick" from the user's
session files. But that is a local problem.
What is more of a problem is tooltips. 

Does the Gambas runtime stick its' own preferences for
Foreground/Background colours into the QT5 environment somehow?

No matter what we try we get what looks like LightGray on dimYellow.

Which is not very readable.
tia
b