These members came from SadConsole as extensions to the MonoGame Color object. They did allow a redefinition (just for flexibility) but with these members being on the primitive type, and SadConsole providing other ways of change color definitions, these should be just as restricted as the normal color definitions.
https://github.com/thesadrogue/TheSadRogue.Primitives/blob/master/TheSadRogue.Primitives/Color.cs#L378
These members came from SadConsole as extensions to the MonoGame Color object. They did allow a redefinition (just for flexibility) but with these members being on the primitive type, and SadConsole providing other ways of change color definitions, these should be just as restricted as the normal color definitions.