Vestifluid is a xenogender/mutogender that changes based off of what one wears or how one presents. The gender does not have to line up with the presentation. For example, one may be agender when presenting femininely, while they are mingender when presenting masculinely, etc.
History
Vestifluid was coined alongside vestiflux by tumblr user awesomenessdoesstuffsometimes on September 13th of 2021.
Flag
The flag was created by the same person on the same day. The meaning is as follows:
"White, black, pink, and blue are picked from the genderfluid flag and have the same meanings they have: no gender, all gender, femininity, and masculinity respectively. The yellow is picked from mutogender but can also mean nonbinary."