Today's Templar dress imitates the original one.
The white dress was reserved for the Knights and symbolized chastity and purity of both the body and the spirit.
The others had to wear a black suit as a symbol of humility.
The red cross, on both mantles, was a symbol of the Blood shed by Christ and a sign of readiness to die in battle.
White, black and the Red Cross are the elements that make up the banner and symbolize the Unity of the order.