I hear you. I actually borrowed some blue and put it on there but it was in the form of a 'chap stick' ? Ie. in a lipstick form (it was genuine locktite) but the thing is, I tried removing the nut after to see how well the blue 'stuck' and it wasn't very strong at all.
At that point I got off my cheap beep and bought some red. I knew the red would stick (from experience) and while being too 'stuck' could be an issue I figured the chances that I would need to take the fan off again, versus the high probabilty the nut would fall off again made me see red
Interestingly enough,
Honda has tons of fans in stock and ZERO nuts. The nuts were back-ordered all the way to Japan...Because the fan is 'captured' and can't fall off this leads me to believe that the stock level on the 4mm nuts is empty for a reason....
From a manufacturers perspective nuts are tiny and dirt-cheap. So really, they should have tons in the system. Where did they all go?
I think your idea of checking yours is valid. My bike was new (700k) when I got it and there was no 'monkeying around' with respect to the fan. That nut backed off all on it's own.....