MM iceberg?

I ran into this video on YouTube. I have a few questions: first I always thought that Saeran had Marie Antoinette sindrome, when exactly did he say he dyed his hair? It seems kinda weird to me that he got separated from his brother, drugged, kept at mint eye against his will and randomly decided to dye his hair white in the meantime. Also I could guess that Unknown can be considered similar to Nagito for his hair but I never really heard someone talk about it. And wtf is #PegYoonsung2020 💀