How to make display name colorful?

[Willowtail x Dapplefur]

Does anyone know how to make your display username colorful? I've seen lots of other people on here with rainbow and other sorts of colors, but how do you do it? I went on customize/edit profile but there doesn't seem to be an option for changing display name colors/style...
I appreciate your help!

[Fawn]

It's part of an upcoming site event! You can find more details about it here.

In preparation for said event, the staff hosted an open call for folks who wanted to livestream during WCOn, and the members who were accepted were given rainbow usernames to indicate their status as official livestreamers.