A set of methods that provides basic behavior for a color picker.
NSColorPickingDefault protocol, together with the
NSColorPickingCustom protocol (which provides implementation-specific behavior), provides an interface for adding color pickers to an app’s color panel.
Configuring Color Pickers
Tells the recever when the color panel's view size changes in a way that might affect the color picker.
A set of methods that provides a way to add color pickers—custom user interfaces for color selection—to an app’s color panel.