At the outbreak of World War 1, the French Army marched to the front lines wearing a dangerously outdated uniform: a vibrant dark blue capote (greatcoat) paired with highly visible, bright red trousers (pantalon garance). Realizing these 19th-century colors made French soldiers easy targets for modern camouflage warfare, the military drastically modernized its kit in 1915. The result was the iconic "Horizon Blue" (bleu horizon) uniform, a light blue-gray wool designed to blend against the sky. Coupled with the protective steel Adrian helmet, this uniform became the lasting symbol of the resilient French infantryman, or Poilu.














