At Hogwarts, you show your colours. At the latest when the stands are packed for Quidditch, everyone can tell at a glance who supports which house: red and gold for Gryffindor, blue and silver for Ravenclaw, yellow and black for Hufflepuff, green and silver for Slytherin. The Sorting Hat has decided, and the scarf tells everyone else.
The Harry Potter Fan Scarf brings that moment to your shoulders. The house scarves for Ravenclaw, Hufflepuff and Slytherin show the house name in large letters across the block stripes, along with the crest or house animal and fringes at the ends. The long versions also feature the house crest. If you prefer something all your own, go for the Luna Lovegood scarf in purple and pink with playful swirls, true to the spirit of the Ravenclaw with the radish earrings. For the dark side there's the Dark Mark, a skull with a snake, in black or grey, and for everyone who doesn't want to pick a side, the Hogwarts crest in gold on black. Only the scarf is included.
For everyone who won't deny their house even in winter. You'll just have to imagine the Sorting Hat's call yourself. ;)