>>536765469
Yes it's a grey horse thing. They actually even talk about it in one of Chrono's career events where all of the white haired umas (from the video below) talk about their experiences and how different they looked when they were younger. Then Curren offers to take a picture of Chrono's hair everyday to see the gradual difference since her hair has been slowly turning white with each passing year

https://www.youtube.com/watch?v=E9kNJd2jk-4

>>534389608
Yes, it's a particular thing with grey horses too and they do talk about it in uma itself sometimes. Chrono's hair for example canonically turns whiter every year according to her profile and career event and it reflects what happened with the horse irl who also turned whiter after retiring from racing