Though it isn't one of Nancy's "glamorous" inks, all of which are good
choices, Waterman Florida Blue (which is Waterman's ordinary shade of
blue, by the way) has a good blue colour, not greenish at all, and is
usually fairly easy to find in stock at ordinary stores (which the
others may not be).

Nancy's suggestions are easy to get by web or mail order, but you won't
find them as easily when you go for a walk.

(Waterman black, on the other hand, is fuzzy grey and not really
black-looking at all.)

David