The 2025-26 Athletic Bilbao Authentic Away Shirt features a sophisticated deep navy base that appears almost black, offering a sleek and modern aesthetic. The design is detailed with striking turquoise accents on the collar, sleeve cuffs, and shoulder inserts, creating a bold contrast. This "Valentia" edition is further enhanced by white sponsor branding and a unique back detail that fuses the Ikurrina flag with an eguzkilore.