If I create a Plain style UIButton using the Storyboard, calling the function setTitleColor(_ color: UIColor?, for state: UIControl.State) stop working, or works in a limited way.
However, the color of the title can still be modified using its titleLabel?.tintColor property.
If I turn UIButton to be Default style, then setTitleColor(_ color: UIColor?, for state: UIControl.State) works as expected.
Thank you
Mauro Bianchelli.