An algorithm to print a Christmas tree to the console

Program.cs

using System;
using System.Threading;
using System.Text;
					
public class Program
{
	public static void Main()
	{
		PrintChristmasTree(20);
	}
	
	public static void PrintChristmasTree(int height)
	{
		Console.ForegroundColor = ConsoleColor.Green;
		var colors = new ConsoleColor[] {ConsoleColor.Red, ConsoleColor.Yellow, ConsoleColor.Blue};

		int middle = Console.WindowWidth/2, indent = middle > 0 ? middle : 50, initialIndent = indent, width = 1, margin = 4;
		string str1 = "MERRY CHRISTMAS", str2 = "AND", str3 = "HAPPY HOLIDAYS!";
		char[] extras = new char[] { '*', '&', '#', '%', 'O' };

		Console.WriteLine();

		for (int i = 1; i <= height && indent > margin; i++)
		{
			var sb = new StringBuilder();
			sb.Append($"{new string('^', width)}");
			var random = new Random();
			if (i == 1) sb[0] = '*';
			else sb.Replace('^', extras[random.Next(extras.Length)], random.Next(sb.Length), 1);
			Console.Write($"{new string(' ', indent)}");
			foreach(char c in sb.ToString())
			{
				if (c == '^') Console.Write(c);
				else
				{
					Console.ForegroundColor = colors[random.Next(colors.Length)];
					Console.Write(c);
					Console.ForegroundColor = ConsoleColor.Green;
				}
			}
			
			indent--;
			width += 2;
			Console.WriteLine();

			Thread.Sleep(200);
		}

		Console.WriteLine($"{new string(' ', initialIndent-1)}| |");
		Console.WriteLine($"{new string(' ', initialIndent-1)}| |");

		Thread.Sleep(200);

		Console.WriteLine($"{new string(' ', indent)}{new string('~', width)}");
		Console.WriteLine($"{new string(' ', indent + ((width-str1.Length))/2)}{str1}");
		Console.WriteLine($"{new string(' ', indent + ((width - str2.Length)) / 2)}{str2}");
		Console.WriteLine($"{new string(' ', indent + ((width - str3.Length)) / 2)}{str3}");

		Thread.Sleep(200);

		Console.WriteLine($"{new string(' ', indent)}{new string('~', width)}");
		Console.WriteLine($"{new string(' ', indent)}{new string('~', width)}");
	}
}

Output

Beautiful and nicely done.