static void Main()
{
Point2D p1 = new Point2D();
p1.ColorIsChanging += new ColorChange(ColorIsChanging);
p1.Color = ConsoleColor.Blue;
p1.Color = ConsoleColor.Magenta;
Console.WriteLine();
Point2D p2 = new Point2D();
p2.ColorIsChanging += ColorIsChanging;
p2.Color = ConsoleColor.Green;
p2.Color = ConsoleColor.Yellow;
}