This was cited as a possible reason for the custom for women to wear white on 15th AV (Taanit 26b):
אמר רבן שמעון בן גמליאל לא היו ימים טובים לישראל כחמשה עשר באב וכיוה"כ שבהן בנות ירושלים יוצאות בכלי לבן שאולין שלא לבייש את מי שאין לו כל הכלים טעונין טבילה ובנות ירושלים יוצאות וחולות בכרמים
Said Chief Rabbi Shimon son of Gamliel -- there were no holidays for the Jewish people like the 15th of Av and Yom Kippur. On those days, the daughters of Jerusalem would wear borrowed white dresses -- everyone would borrow someone else's dress, to not embarrass someone who didn't have one -- and dance in the vineyards ...
I was not aware that women were supposed to wear white on Yom Kippur. I would think that this is NOT the same reason for a man wearing a white Kittel on Yom Kippur. Please clarify this seeming anomaly for me. Thank you.