#!/usr/bin/perl
use strict;
use warnings;
use Win32::API;

#Private Declare Function GetDC Lib "user32" (ByVal hWnd As Long) As Long
Win32::API->Import(
    'user32', 'long GetDC(long hWnd)',
);  

#Declare Function GetPixel Lib "gdi32" Alias "GetPixel" (ByVal hdc As Long, ByVal x As Long, ByVal y As Long) As Long
Win32::API->Import(
    'gdi32', 'long GetPixel(long hdc, long x, long y)',
);  

sub PixelColor {
  my ($x, $y) = @_;
  my $dc = GetDC('');
  my $rgb = sprintf "%06x", GetPixel(GetDC(''), $x, $y);
  return $rgb;
}

print PixelColor(100, 100), "\n";