Athletico Bilbao paly in read and white strips, beacuase of the Saints:
Atletic Bilbao began playing in an improvised white kit, but in the 1902-03 season the clubs first official strip became half blue, half white shirts similar to those worn by Blackburn Rovers, which were donated by Juan Moser. Later a young student from Bilbao named Juan Elorduy, who was spending Christmas 1909 in London was charged by the club to buy 25 new shirts, but was unable to find enough. Waiting for the ship back to Bilbao and empty handed, Elorduy realised that the colours of the local team Southampton Football Club matched the colours of the City of Bilbao, and bought 50 shirts to take with him. Upon arriving in Bilbao, the clubs directors decided almost immediately to change the teams strip to the new colours, and since 1910 Athletic Club have played in red and white stripes. Of the 50 shirts bought by Elorduy half were then sent to Atlético Madrid which had originally begun as a youth branch of Bilbao. Before the switch from blue & white to red & white, only one other team wore red & white, Sporting de Gijón, since 1905.[3] [4]