What I found out was that whenever I close my laptops' lid, my laptop doesn't go into the 'sleep' mode and it keeps on running, which never happened before. it seems to go back to black and white/grey scale again. and it worked! But the real problem is that, whenever I close my laptop and open it. It was working fine until few days ago, when I closed my laptop's lid and reopened it later on, the screen was black and white/grey scale. Yes, in order to fix it I uninstalled my display driver then I reinstalled the current driver.
I had the latest driver from NVIDIA's website, Version: 195.62, for my graphic card.
I have Dell Inspiron 1520 laptop with NVIDIA Geforce 8600M GT.
