When I was at school I alternated between blue and black quink for my Parker pen. Sometimes I used to buy silly colours like turquoise or green or brown. Like yourself I thought black was less forgiving and that blue tended to look better presented. If you produce a page in black with no scribbles or blots, though, it does look rather more impressive than blue. I think it's just the strength of the colour and the fact that mistakes are far more visible in black.

I've heard it said that ladies use blue ink and that gentlemen use black or blue-black. I expect this is just old-fashioned, English nonsense.