I want customizable color schemes and fonts and sizes. It's nice as a user to pick full-on custom themes. Sadly even though Qt is based around theming, I had to

I want customizable color schemes and fonts and sizes. It's nice as a user to pick full-on custom themes. Sadly even though Qt is based around theming, I had to turn off theming for semi-customized controls (colored sliders) to make them render correctly on Windows and Linux Breeze/Fusion. And it's more work to verify my app looks good across OSes when QButtonBar and QFormLayout change appearance on different OSes. So finding a good solution is nontrivial.