The labeled section is called the renal capsule. This layer is tough and it surrounds the kidney. The renal capsule is covered in fat, which is called the adipose capsule of the kidney. It is made of fibres, elastin, and collagen.
The purpose of the renal capsule is to provide support for the kidney mass and protect the kidney from any injuries. In most people the capsule is a reddish, purple color. This color can be seen as translucent and smooth. As one increases in age, so does the amount of fibres found in the capsule.