Aqua Blue is a bright turquoise blue, with the tiniest little bit of pink sheen. Seasonally, this is a summer ink.
You can see the tiniest little bit of pink sheen on the edges of the ink drops on Tomoe River.
Feathering: Aqua Blue only low feathering on the Baron Fig paper, with no feathering on the other papers.
Bleeding: Aqua Blue had low bleeding on Baron Fig paper, with no bleeding on the other papers.
Ghosting: Aqua Blue had low to medium ghosting on all of the papers.
Shading: Aqua Blue had low shading on all of the papers, with sheen only on the ink drops on Tomoe River.
Lamy Pacific Blue is the closest ink to Diamine Aqua Blue, but it is still darker than Aqua Blue.
Overall, I think Aqua Blue is a good summer ink, and it behaves consistently on all of the papers. I think it's a nice turquoise, it just lacks an x factor to help distinguish it from similar inks. It actually seems like the poor man's Lamy Pacific Blue, which has more shading, more sheen, and is a little bit darker. Below is a link to where you can find this ink on Amazon.
Disclaimer: I purchased this ink myself, and all opinions and photos are my own. This page does contain an affiliate link.