One of the key accessories for 盆踊り (bon odori) is the flat fan or 団扇 (uchiwa). The best ones are made by creating a bone skeleton with bamboo from 四国 (Shikoku), on which 和紙 (washi, Japanese paper) is glued.
At this year's パロアルト (Palo Alto) お盆 (obon), I noticed that instead of the usual artistic fans with delicate designs, many dancers were wearing plastic fans like those handed out in hot summer nights by beer companies as marketing tools. I was surprised—with the consul here, why something so tacky?
It was only as the dance progressed and dusk had my vision switch from photopic to mesopic, that I discovered the secret. Today's flat fans are made with designs created by elaborate multicolored LED patterns and wave guides molded in the plastic fan. As the day wanes and vision progresses towards scotopic, these modern 団扇 (uchiwa) become eerie, creating an atmosphere where the living look more like the dead ancestors coming to visit us during お盆 (obon).
Scary! Has 四国 (Shikoku) been unsealed and become 死国 (Shikoku)?
And now to the challenge for color imaging. Below are photographs of paroaruto's bon odori in chronological order. As you note, the camera remains photopic. It cannot render correctly the fan color appearance and the scariness has completely disappeared.
Back to the drawing board! We need color rendering algorithms that can reproduce accurately the color appearance of contemporary flat fans.