I change my characters' hairstyles to match the season or new outfits sometimes. I also change their hair when I get sick of it always being the same way.
Right now it's red hair. It's either in ponytail or a bun. The colour works with my favorite clothing.
My other town has navy blue hair and it's in a bun.
I haven't changed it in a long time, I'm happy with the one I have had for almost a year. I experimented with a few different haircuts at first but settled on one. Every once in a while I might try something new but I always seem to come back to the same one.
I haven't changed my mayor's hairstyle in a while. But I did change her haircolour from blonde to reddish-brown not too long ago. her winter outfit with blonde hair washed her out, so i changed it.
I honestly haven't changed my hairstyle since when I first got the game. I'm not really crazy about the hairstyles for girl villagers so I feel as if the one I have right now is the best one. Although, I have been wearing the hairbow wig thing!
I think I've only changed my hairstyle maybe twice in the year that I've been playing the game. I guess it's because it's kinda hard for me to get the shade or brown I want, lol. Thank goodness for wigs!
I only change the hair color for Winter. (Dark Brown the first days of December, and then Blue.)
I change it back to normal when I get bored of it or when Spring arrives.