Single-mode fibers typically use yellow or blue jackets, with green for APC fibers. Red and black indicate backup or special-purpose fibers. Each of these colors signify something very specific and we know based on these colors what they mean and what we are supposed to do. There are six fundamental colors in the visible spectrum – These are red, orange, yellow, green, blue, and. Understanding fiber‑optic color codes is essential for any technician tasked with installing, maintaining, or troubleshooting modern fiber networks. The aqua color (hex: #00B6C1) is instantly recognizable and signals support for 10, 40, or 100 Gb/s over short distances — up to 300 meters at 10G.