public SolidBrushViewModel(BrushPropertyViewModel parent, IReadOnlyList <string> colorSpaces = null)
 {
     Parent                  = parent ?? throw new ArgumentNullException(nameof(parent));
     ColorSpaces             = colorSpaces;
     parent.PropertyChanged += Parent_PropertyChanged;
 }
 public MaterialDesignColorViewModel(BrushPropertyViewModel parent)
 {
     Parent = parent ?? throw new ArgumentNullException(nameof(parent));
     parent.PropertyChanged += Parent_PropertyChanged;
 }