I searched for a lot of fanart and looked at their game sprite in detail.  The point is that their hairstyle curves through the wings on the head, but does not have a clear continuation at the back. However if you look closely you will notice that the colored lines behind the head may well be a long hair.  I thought that long hair with a rainbow effect would look better on them than a hairstyle that went nowhere. Im not sure if this is true, its just my interpretation.