US Army 001St Cavalry Division Full Color Patch – PM0018. The 1st Cavalry Division’s Shoulder Sleeve Insignia, or unit patch, communicates the units mission and history with only two colors and sparse graphics. Since 1855, when yellow first replaced orange and ‘cavalry’ was first used in place of ‘dragons’ yellow has been the traditional color of cavalry. The color black, on the other hand, is an homage to the units transformation from horses to tanks and armored vehicles and is the color of iron. The diagonal stripe, which also serves as a representation of military honor in heraldry, symbolizes the division aggressive behavior in battle by suggesting forward mobility. The lone horsehead not only acknowledges the division’s beginnings as a group of mounted soldiers but also displays the numerical designation of the unit.