The elite imperial army was hierarchically divided in colors: yellow, white, red and blue. The social status of the warrior class was a hereditary privilege that included a house and a salary.
This satiny jacket is part of the uniform of a soldier of the “blue flag”. It was covered by protective flaps in the neck, shoulders, chest and arm as well as leg protection and the helmet.
The metal pieces are present in all the uniforms of the elite force including the horse armor. From the ceremonial military attire of the Qing emperor himself to the uniform of the lower-ranking elite guard like the blue guards, they were covered with these metallic semi-spheres.