How to change NSPopover background color include triangle part?

Question

How can I change NSPopover background color include triangle part?

Answer 1

The solution by Mike Bedar is working, but with adding just one more thing (in order to get the triangle filled with background color), and that is to override the draw function inside the PopoverContentView as well:

 override func draw(_ dirtyRect: NSRect) {
    backColor.set() // backColor is NSColor
    NSRectFill(self.bounds)
}