Of all the inks I have, maybe Diamine Tropical Blue and Swishmix Antigua blue come closest to what I'm looking for. Basically, I'd like a _bright_ blue that is saturated but not too dark. Navajo turquoise, for example, is perhaps the brightest blue I've seen, but it tends heavily towards turquoise. PR DC supershow blue is very nice, but too dark. Noodlers blue is also darker than what I'm looking for, while aquamarine blue is not very bright (it may be light but not bright) and has grey in it.
Diamine tropical blue, on the other hand, is lighter than I'd prefer.
If you have a suggestion (other than I should stop buying blue ink
Stephen