The reason the club changed colours is not known for certain. However one theory is that red and white striped tops were the cheapest stripes to make because the same combination was used to make bed mattresses. The left over cloth was easily converted into football shirts. Although both Athletic Bilbao and Athletic Madrid started out with blue and white stripes, the discovery of a cheaper option probably persuaded them to change. The Madrid club did it first and they became known as los colchoneros—the mattress makers. Other more plausible account of the reason to change colours is that both Athletic Bilbao and Athletic Madrid used to buy Blackburn Rovers blue and white kits in England.