Thanks guys! I never would have guess that red meant gust. (And, AFAIK, there's no HTML-like help page or a "tap on this icon" with a question mark thingie to get specific help, like Windows has.) As I said earlier, I thought that maybe iFly was trying to warn us that anything over 30 knots was dangerous.
I don't see the red barb as intuitive. But, at the moment, I can't think of a clever way to graphically indicate a gust. Anyone got any ideas? How does NOAA do it? (I'll be embarrassed if they use red too.)
I suppose that one red barb means that the winds are gusting 10 kts? 'Cause I was going to suggest that perhaps the entire barb indicator be red when large gusts. But that wouldn't work if individually colored barbs conveyed information.