Fiber optic pigtail is an unbuffered optical fiber that has one end terminated with a fiber optic connector and the other end prepared for splicing. This article delves into the significance of green and blue fiber ends, exploring their differences, applications, and how to choose the right one for your needs. Fiber optic connectors are devices used to terminate the end of an optical fiber and enable quicker connection and disconnection than. Apart from fiber end faces, a distinct difference is color. Generally, UPC connectors are denoted by blue, while APC connectors are associated with green.