Ben Shneiderman developed "TIES" aka "HyperTIES" at the University of Maryland Human Computer Interaction Lab, and here's what he recently wrote in response to a question about hyperlinks, in which he mentioned the origin of blue as a highlighting color.

Also here's a link to an article about the NeWS version of HyperTIES that we developed at HCIL, and some demos of HyperTIES and its Emacs based authoring tool, which had pie menus and embedded interactive PostScript "applets" in 1988.

https://medium.com/@donhopkins/designing-to-facilitate-brows...

HCIL Demo - HyperTIES Browsing

https://www.youtube.com/watch?v=fZi4gUjaGAM&ab_channel=DonHo...

HCIL Demo - HyperTIES Authoring with UniPress Emacs on NeWS

https://www.youtube.com/watch?v=hhmU2B79EDU&ab_channel=DonHo...

Don Hopkins and pie menus in ~ Spring 1989 on a Sun Workstation, running the NEWS operating system.

https://www.youtube.com/watch?v=8Fne3j7cWzg&ab_channel=Cathe...

John Gilmore via Internet-history <internet-history@elists.isoc.org>
Date: Mon, Apr 13, 2020, 11:56 PM
To: Brian, internet-history, Jeff

I forwarded this question to my friend Don Hopkins, who was a student of
Ben Shneiderman back in the day. Ben ultimately responded:

From: Ben Shneiderman <ben@cs.umd.edu>
To: Don Hopkins <don@donhopkins.com>
CC: John Gilmore <gnu@toad.com>, Ben Shneiderman <ben@cs.umd.edu>
Subject: RE: [ih] origins of the term "hyperlink"
Date: Mon, 13 Apr 2020 15:15:52 +0000

HI Don (and Jack Gilmore),

Thanks for including me in this conversation.

I do not have a claim for the term “hyperlinks” and don’t know when it
came into use. My claim is for the visual interface for showing
highlighted selectable links embedded in paragraphs. This is what we
called embedded menu items in that I think is an influential paper on
the topic, which was peer-reviewed and published in the CACM in April
1986.

https://dl.acm.org/doi/10.1145/5684.5687

http://www.cs.umd.edu/~ben/papers/Koved1986Embedded.pdf

While Engelbart had shown a list that could be selected by pointing
and clicking in 1968, I claim the idea of embedded highlighted
selectable text in paragraphs. This was implemented by grad student
Daniel Ostroff and described in:

Ewing J, Mehrabanzad S, Sheck S, Ostroff D and Shneiderman B (1986),
"An experimental comparison of a mouse and arrow-jump keys for an
interactive encyclopedia", International Journal of Man-Machine
Studies, Jan., 1986, Vol 24, pp. 29-45.

[Abstract] [BibTeX] [DOI]

Ostroff D and Shneiderman B (1988), "Selection devices for users of
an electronic encyclopedia: an empirical comparison of four
possibilities", Information Processing and Management, Nov., 1988,
Vol 24(6), pp. 665-680.

[Abstract] [BibTeX] [DOI]

I think the 1988 paper was the earlier study, but the publication took
a while.

My students conducted more than a dozen experiments (unpublished) on
different ways of highlighting and selection using current screens,
e.g. green screens only permitted, bold, underscore, blinking, and I
think italic(???). When we had a color screen we tried different color
highlighted links. While red made the links easier to spot, user
comprehension and recollection of the content declined. We chose the
light blue, which Tim adopted.

His systems with embedded menus (or hot spots), where a significant
user interface improvement over early systems such as Gopher. But Tim
told me at the time that he was influenced by our design as he saw it
in the Hypertext on Hypertext project that we used Hyperties to build
for the July 1988 CACM that held the articles from the July 1987
Hypertext conference at the University of North Carolina. The ACM sold
4000 copies of our Hypertext on Hypertext disks.

Our history is here:

https://www.cs.umd.edu/hcil/hyperties/

and the video is very helpful in showing the design we used, which is
what I think Tim built on for his WWW prototypes.

https://www.youtube.com/watch?v=29b4O2xxeqg

So in summary, I don’t know who coined hypertext, but I do think our
work visual and interaction design was influential.

Our Hyperties system was picked up by Cognetics Corporation (around
1987) who made a modestly successful commercial run with it, doing
dozens of corporate projects, most notably the Hewlett-Packard user
manual for their Laserjet 4 was distributed as a Hyperties disk.

Hyperties was the name we shifted to after we got a stop and desist
order from a lawyer because our TIES (The Interactive Encyclopedia
System) conflicted with an existing product. By then “hyper” was a
growing term.

Let me know if this helps, and what other questions you have…. Ben