Phil-
Dalton is correct. You can use up to a 7wt for the CI test. While you can accomplish the CI with a lighter weight rod/line, make it easy on yourself and use a 7wt. They want you to show smooth, relaxed demonstation casts with nice loops, not your typical fishing casts. On a windy day, it will be easier with a 7wt.
I saw some folks use chartreuse flylines for the test and it worked fine. However, I believe the orange line is easier to see for the folks giving the test, even in bright sun. If they can't see your line during a cast, they will ask you to do it again. Just make it easier for everyone and use an orange line.
The ballistic line has a long head with the rear taper ending at 55'. It is a good line that is especially nice for the roll casting, hauling and distance casting parts of the test. Regan also used that line when he took his test. He was the one who recommended the line to me.
As I mentioned earlier, I will bring both the 6wt and 7wt orange ballistic lines to the next casting church, in case you want to try them out.
-Tom