Kvantum is very limited, providing support -only if there is a kvantum theme for it.
I tried it on Zorin... and immediately nuked it off my machine, never to be seen again.
I am sorry, I did not see your post from 28 days ago- or I was in a hurry and forgot it... But I have found a bug in Zorin OS since then that sets the QT_STYLE_OVERRIDE to gtk3 instead of gtk2. That file must be changed to gtk2 for the qt5ct settings to work.
No worries, thanks for your help. After I did this and restarted my pc, my panel's icons disappeared, but it didn't happen again after few tries. I wanted to update the post for helping others like me, white color hurts eyes a lot at night