The ConsoleColor enum has 16 values.

C# Code:
  1. var random = new Random();
  2. for(var i; i < 100; i++)
  3. {
  4.      Console.ForegroundColor = (ConsoleColor)random.Next((int)ConsoleColor.Black, (int)ConsoleColor.Yellow);
  5.      Console.BackgroundColor = (ConsoleColor)random.Next((int)ConsoleColor.Black, (int)ConsoleColor.Yellow);
  6.      Console.WriteLine(i);
  7. }