Weird dark line beside hairstyle

[Adel]

I noticed that on certain hairstyles, when changing palettes some of them would cause this dark line to appear on the side.
This only happens with a couple hairstyles. It doesn't seem to be coming from the sprite or the act. Does any one know what could be causing this?

[Sapito Sucio]

Mmmhh I have noticed it too

[Thanna20]

same here, noticeable specially when you rotate the camera at 45 degrees. I even tried to extract the hair sprite clean the edges and combined it all together but that line is still there.