Ha, glad it's not just me then. The amount of times I've seen/heard people trying to lock is way over the potential 10% of men that are colour blind

I don't think you should feel ashamed, it sounds like you're doing it right. It's the other end of the 'noise' spectrum you hear that is more disconcerting (machine gun etc.)I feel awkward when people are in the toilet and I drop an absolute log. The splash makes me cringe.