using System.Runtime.InteropServices;
[DllImport("kernel32.dll")]
public static extern bool SetConsoleTextAttribute(IntPtr hConsoleOutput, int wAttributes);
[DllImport("kernel32.dll")]
public static extern IntPtr GetStdHandle(uint nStdHandle);public static void Main(string[] args)
{
    uint STD_OUTPUT_HANDLE = 0xfffffff5;
    IntPtr hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
    // increase k for more color options
    for (int k = 1; k < 255; k++)
    {
        SetConsoleTextAttribute(hConsole, k);
        Console.WriteLine("{0:d3} I want to be nice today!", k);
    }
    // final setting
    SetConsoleTextAttribute(hConsole, 236);
    Console.WriteLine("Press Enter to exit ...");
    Console.Read(); // wait
}
منبع : http://www.daniweb.com/code/snippet134.html