Student or Learner
Everyone on stage was dressed in flowing white robe(s).
After everything/body/one, do you suggest using plural nouns or singular nouns?
Which one do you feel better to use?
Definitely singular for the verb.
Logically it should be singular for nouns - a flowing white robe.
However, you'll often hear/see plural nouns here; it's particularly common with parts of the body: Everybody shook their heads.
I wouldn't worry about it.