PowerBook - Disk Utility has lost its connection with the Disk Management Tool & cannot continue

Whenever I try and Repair or Verify Disk Permissions on Disk Utility it stops and the following message appears. I quit and relaunch disk utility and it just does the same thing with same message.

"Disk Utility has lost its connection with the Disk Management Tool and cannot continue. Please quit and relaunch Disk Utility."

I tried doing this as my powerbook has suddenly developed a turquoise hue across the whole screen. They are actually small rectangles and columns. It cropped up randomly. I turned off the computer and left it off for a good few hours and its still there. They kind of come and go on different parts of the screen now. Its just making everything have a turquoise tint.

Any help would be much appreciated!

Thanks