Hello! I think know what you mean. A way to get your mane to look this way takes a bit of knowledge with an art program such as Gimp or Sai. I use Paint Tool Sai for most of my editing and art needs. However to make things easier, I have the same mane style here:
If the file is not named this already, rename the file to: fmaneLight.jpg
and drop the image file into your textures > masks folder!
When the game asks you if you want to replace the older file, click OK/Yes!