Which type of optical fiber jacket color indicates it is for outdoor use?

The jacket color of an optical fiber cable can convey important information about its intended application and environment. In the context of outdoor use, black is the color typically designated for cables that are meant to withstand harsh environmental conditions. Black cables are resistant to UV light and other outdoor hazards, helping to protect the fiber optic elements from degradation caused by sunlight exposure and various weather factors.

In contrast, other colors have specific uses; for example, yellow is often used for indoor multimode fiber, and red may represent specialized cables such as those for fire protection, while gray is commonly associated with indoor applications as well. Hence, the black jacket color signifies that the optical fiber cable is suitable for outdoor deployment and can endure the elements, making it the correct choice for this question.