This is Gunther, who is a Norwegian Fjord and belongs to one of my friends/clients. Most of the time his mane looks like this: with creme colored hair on the sides and black down the center. This is considered a primitive marking and goes with the stripes on his legs, hearkening back to an earlier evolutionary version of the horse.
My friend is creative, however, an had a good time styling Gunther's mane this week. Just a little bit of trimming in an unusual way gives him this dapper checkerboard style!