Biased from the above context, blue fiber cables are being defined as the cables which have a blue color jacket and come into the category of MMF. It means such cables are able to transmit within a core several light signals since they are made to support many modes of light. There are different types of fiber optic cables, and multi-mode fiber is one of the most widely used because it is effective and economical for communication over short to medium distances. Because of this, more. Of course fiber optical cable (in general) is considerably more durable since this frantic refrain from the past, and has evolved over the years. This small diameter core, typically around 9 microns in diameter, allows only one mode of light to pass through, resulting in a narrower beam of light. Let's take a closer look at the colors for multimode fiber types.