WebcamTexture GetPixel not working

I am using a Logitech Webcam for my unity project.I am trying to get rgb values for my webcamtexture.But all I get is 0,0,0,1.Here's my code:

   WebCamDevice[] devices = WebCamTexture.devices;
         WebCamTexture webcamTexture = new WebCamTexture();
         if (devices.Length > 0) {
             webcamTexture.deviceName = devices[1].name;
             print (webcamTexture.deviceName);
             webcamTexture.requestedHeight = 400;
             webcamTexture.requestedWidth = 400;
             webcamTexture.Play();
             print(webcamTexture.isPlaying);
             print(webcamTexture.GetPixel(200,200));
             while(pl!=100)
             {
             if(webcamTexture.didUpdateThisFrame == true)
             {
                 print(webcamTexture.height);
                     print(webcamTexture.GetPixel(200,200));
             pl++;
                 }
             }
         }

The Webcam was successfully detected(even the webcam light was on) but I am always getting 0,0,0 as my rgb values when I use GetPixel.Please help.