public override bool Equals(object obj)
        {
            if (!(obj is CmykColor))
            {
                return(false);
            }
            CmykColor c2 = (CmykColor)obj;

            return(Cyan.ApproxEquals(c2.Cyan) && Magenta.ApproxEquals(c2.Magenta) && Yellow.ApproxEquals(c2.Yellow) && Black.ApproxEquals(c2.Black));
        }