I am using following code for my status bar image:
let icon = NSImage(imageLiteralResourceName:"flag")
statusBarItem.image = icon
This leads to wrong color for certain background colors / modes. In the picture, what's white should be black. The image resource is white/transparent. If I change that, I get the same problem. All other status bar images will turn white on certain configurations, mine will stay black.
I was thinking that MacOS would add effects to make all statusbar icons look uniform on it's own, but apparently thats not the case...
Any ideas how to fix that?
Thanks!

I found a solution. Again I realize that MacOS development is way less supported by Apple than iOS. I think the color adjustment of statusbar icons should be the task of the operating system, but Apple lets the developer do the work. Whatever.
Here is the solution:
You have to provide two versions of your icon, one in black, the other in white.
When the app launches, you have to check wether the user's MacOs is in dark or light mode. This can be done with following code:
One problem remains here now: When the user changes the mode while your app is running, the icon color won't update. Also: If the user uses the automatic mode (i.e. it's light at day and dark in the night), the icon color won't switch as well.
You can tackle that problem by listening to a certain notification that is fired when the dark mode settings changes:
In my tests, this worked in all scenarios.