I agree with Smeggy that there's a delay (1 or 2 seconds), although you'd think that they would have done away with it by now due to revenue. Perhaps it's part of the type approval; I can't believe it's a fundamental limitation of the technology.
I also agree that (AFAIK) red light cameras always flash. Assuming it was a "normal" red light camera (i.e. one of the older non-digital ones which isn't a speed camera as well), they flash pretty brightly and unmistakeably. There are 2 flashes a second apart. It's very difficult to miss if you're anywhere near it, even if it's behind you and it's daytime.
So I think you'll be all right. But if you do get a fine, then yes, it has to be sent within 14 days (and it has to be sent first class, among other things). If that happens then you can seek further advice here, although TBH, those who jump reds tend to get less sympathy here than speeders. I realise it was marginal in your case (if it was red at all), but unlike speeding most of the time, it can be extremely dangerous, so please try not to do it.
(In theory one shouldn't even go through on amber unless they can't stop, but these days there are so many unnecessary lights, and such short green phases, that the "expected behaviour" seems to be to treat amber as "get through ASAP". Just another way in which the authorities have made our roads so much safer and more pleasant through their persecution of the motorist....)
Relax, you'll be fine.