- iOS 6.0+
- macOS 10.0+
- tvOS 9.0+
- watchOS 2.0+
The value of this parameter is a
UIColor object. If it is not defined (which is the case by default), it is assumed to be the same as the value of
foreground; otherwise, it describes the outline color. For more details, see Drawing attributed strings that are both filled and stroked.