public virtual ExcelColors BackKnownColor { get; set; }

Public Overridable Property BackKnownColor As ExcelColors
	Get
	Set

public:
virtual property ExcelColors BackKnownColor {
	ExcelColors get ();
	void set (ExcelColors value);
}

abstract BackKnownColor : ExcelColors with get, set
override BackKnownColor : ExcelColors with get, set