TabPanel Cross Platform WYSIWYG

On a Desktop project that compiles for Mac and Windows, I am using a dark coloured background on the Main window.
This works ok for most controls, but not for TabPanels:
On Mac, They nicely take on the color of the Main Window, but on Windows, the tabpanel is always white.

I know I can put a rectangle inside the tabs, but I’m wondering if there is a better way?
I would prefer to have the tabs them selves different from the standard windows look also.

Is there any non sloppy and flickering causing way to do this?

Guess you have to draw the control yourself using canvasses.