Why is my galaxy s3 touchscreen unresponsive

Hi,

I have a Samsung Galaxy S3,

I woke up this morning and noticed my screen was completely pink, after removing the battery a few times and starting it up the screen become black and green and slowly turned pink again. I removed the battery for about an hour and then put it back in, the phone was able to start up with all its sounds and I was able to see the home screen, unfortunately the screen was unresponsive, I removed the battery again for about an hour and then I was able to get passed my security pin after it booted up, after that the screen became unresponsive again and this is where it has remained, the battery removal doesn't seem to have an effect anymore.

Everything else seems to be working i.e. incoming phone calls, msg's etc but just not the touch screen - Any Ideas on how to fix this?