she explained she wanted me to eat more balanced and did it in hopes that i'd turn back. recently i have decided to go back though. but simply only lean meats
multi-color streaks often mean a cable or card is loose. Make sure the vga/dva cable is properly connected, and re-seat the card afterwards if still issues (and comfortable with the task).
We had a few of the old Macs and when the displays went bad they started getting the multicolored vertical lines. Imacs don't have VGA cables though, I'm thinking vid card or monitor.