2003. It was blue on a white background and looked a little too much like the national flag for Israel. That idea got dropped really fast at that point.
From a news article:
The new flag, which is being publicly unveiled today, is made up of two blue stripes representing the Tigris and Euphrates rivers separated by a yellow stripe symbolising Iraq's Kurdish minority.
The stripes are topped by a white space featuring an Islamic crescent in the middle.
Many Iraqis have strongly criticised it, complaining that it does not sufficiently represent Iraqi civilization and its Arab majority.
They say it gives too much importance to the Kurdish minority, and that its pale blue colour makes it look like Israel's flag.
They are furious that the new flag will no longer feature the colours red (for nationalism), white (for peace), and black and green (for Islam), nor the three stars which they viewed as symbolising Iraq's modern history.