You always have to pay attention to two color axes: red-blue, and magenta-green. The overhead fluorescents are probably roughly daylight (cool whites,) though they could be roughly tungsten (warm whites.) If they appear to be warm whites, you will need to warm up your light a lot; It is possible the "amber" filter will work. So much for the red-blue axis. Assuming the overheads are 'daylight,' your LED is probably too blue by a bit. I'd tape on a 1/4 CTO to warm the light up slightly.
Consumer fluorescents all have a green spike. You therefore need to add green to your light to match the overheads. I'd bring along a couple of pieces of 1/4 plusgreen cut to size to tape over the light. Start with just one layer.
Now white balance to a gray card with a mix of overheads and your light. Ideally you'd want to play back a test shot on a good, large, color-critical monitor, but you probably won't have access to one. So you'll have to evaluate on the camera's tiny screen. Or by eye.
It's also possible the convention hall has some other type of overhead lighting. Equally, booths may have different lighting. In all cases, you want to make your little light match as closely as possible whatever is up there. If at all possible, go in a day before and shoot tests!
Since you are shooting b-roll, that suggests someone else is shooting the a-roll. Confer with that shooter. S/he is really the boss here.
Rick Wise
Cinematographer
San Francisco Bay Area
http://www.RickWiseDP.com
