Screen tinting code for C#

ScreenTint.cs

// Created by flarn2006 <flarn2006@gmail.com>
// Licensed under MIT License

using System;
using System.Runtime.InteropServices;

namespace YourNamespaceHere //TODO: change me
{
	static class ScreenTint
	{
		[DllImport("user32")]
		private static extern IntPtr GetDC(IntPtr hWnd);

		[DllImport("gdi32")]
		private static extern bool GetDeviceGammaRamp(IntPtr hDC, [Out] short[] lpRamp);

		[DllImport("gdi32")]
		private static extern bool SetDeviceGammaRamp(IntPtr hDC, short[] lpRamp);

		private static IntPtr hDC;
		private static short[] originalRamps;

		static ScreenTint()
		{
			hDC = GetDC(IntPtr.Zero);
			originalRamps = new short[768];
			GetDeviceGammaRamp(hDC, originalRamps);
		}

		public static void Tint(byte red, byte green, byte blue)
		{
			short[] ramps = new short[768];

			for (int i=0; i<768; i++) {
				byte value;
				if (i < 256)
					value = red;
				else if (i < 512)
					value = green;
				else
					value = blue;

				byte orig = (byte)((originalRamps[i] & 0xFF00) >> 8);
				ramps[i] = (short)(value * orig);
			}

			SetDeviceGammaRamp(hDC, ramps);
		}

		public static void Restore()
		{
			SetDeviceGammaRamp(hDC, originalRamps);
		}
	}
}