I kinda made it work with QIcons, the dark icons [#373737] looks nice except for softness.
I followed how Krita Icons are saved which are 22 x 22px svgs in two modes light and dark.
Soak Ink one is a pretty fun icon cause it dunks the brush 
softness needs work, a bit of adjustment to paintmode.
OTH dark theme light icon ver needs alot work.
[idk how to work pixmap so i just qicon from file. I think i need a way to know if the theme is dark or light]