Here is the list of the Iron Man armors shown on the movies, Iron Man and Iron Man 2.
The first of the Iron Man armor creation. Made by Tony Stark while he was trapped by the terrorists in a cave. Can't withstand heavy artillery attack and its flight mechanism didn't work successfully. Left scattered in the desert and collected by the terrorists later on.
The next Iron Man armor prototype developed by Tony after he escaped from the terrorists. With the assistance of the high-tech machinery tools in his home lab, he significantly improves the armor. Still, there were various hiccups during the initial testing sessions.
After some pilot tests done on the Mark 2, Tony solves the technical problems and issues by building the Mark 3 armor. Designed with the red and gold colours, the armor looks more outstanding and amazing.
Iron Man's Mark 4 doesn't look much different from the Mark 3. Only with minor design improvements, there isn't much changes with the colour. Technical wise, perhaps a little adjustments here and there.
The Mark 5, also known as the suitcase armor, made its movie debut appearance on Iron Man 2. Tony used it after he was attacked by Whiplash at the racing track. Comes in a form of a suitcase, it's portable and can be easily brought anywhere. Certainly comes in handy.
The Mark 6 is the latest armor made. It's still built with the same colours, but the shape of the miniature power reactor (which is normally circle) at the middle of the chest has changed to triangle. Minor amendments to the exterior design is noticeable as well.
