The phrase (and maybe the very idea of) “pseudo green hair” was introduced to the public in this trichological study:
“Pseudo Green Hair,” Xavier Tomas, Marina Nogueras, Alvaro Bartolome, and Juan Ferrando, International Journal of Trichology, vol. 14, 2022, pp. 65-7.
The authors report: “we present a case of green hair highlights, coinciding with the application of a cosmetic hair procedure (Californian highlights) prior to swimming in a pool with increased copper content. Since, conceptually, green hair is due to copper deposition on the hair, another cause of green hair should be named pseudo green hair, as in our case.”
Earlier: Rewarded Green Hair Research
The 2012 Ig Nobel Prize for chemistry was awarded to Johan Pettersson for solving the puzzle of why, in certain houses in the town of Anderslöv, Sweden, people’s hair turned green.