Messenger Plus! let users add colours and formatting to a display name. People with a compatible extension could see the intended appearance; others might see the formatting characters mixed into the name.
Why the same name looked different
The display name was not simply plain text once formatting instructions were added. The receiving client needed to understand those instructions to draw the colours, bold text or background the sender intended.
The old article used that difference to explain why a contact's nickname could look like a string of letters, numbers and symbols in another installation.
The colour-number idea
The original walkthrough introduced a numbered palette. Its examples included white at 0, black at 1, green at 3, red at 4, orange at 7, olive at 10 and dark grey at 14.
A formatting instruction selected a colour for the text that followed. Selecting another colour later in the name changed the appearance of the next portion. The precise control characters were specific to the old client and are not ordinary web styling.
A bracketed alternative
The source also showed a bracketed form such as [c=12]name[/c]. In that example, the opening instruction selected a colour and the closing instruction ended it.
This syntax is preserved to explain the historical feature, not as a claim that it works in a current messaging service. Text that looks like markup in one client may be displayed literally in another.
Alternating colours
The article's practical example used the name CAROLINA, alternating dark-grey consonants with orange vowels. Its point was that several formatting changes could be combined inside one displayed name.
Although that made personalisation more flexible, a complicated name could also be harder for someone else to read or identify. Compatibility and legibility mattered as well as decoration.
Part of a wider extension
Colourful names were one of several Messenger Plus! features. The extension also dealt with conversation tabs, custom statuses and logs, described in the main feature article.
This page records how people customised a particular older application. It does not provide an installer or recommend recreating that setup on a current computer.