[tialaramex]

Coloured book protocols (X.25 based networking) existed at some UK universities as late as 1997, it was still possible to use this network when I was an undergraduate in 1995, but the service was no longer available by the time I graduated.

Here is a link to a site describing a system that you could use (probably considerably earlier than 1997) to access the Internet (in this case an FTP server) despite only yourself having X.25, via hhcp:

http://deslab.mit.edu/UNIXhelp/guestftp/index.html