Fiber optic patch cords come in various colors, aiding in connector type identification. Pro tip: Jacket color standards are part of. Color-coding is a big help when identifying individual fibers, cable, and connectors. These colors are typically chosen by industry standards bodies. However, there are some. Outer jacket color: Generally speaking, the outer jacket colors of OM3 and OM4 fiber optic patch cords are lake blue and purple, while the outer jacket color of OM5 fiber optic patch cords is aqua green. OM1. If you've ever opened a comms closet at your school and seen a rainbow of yellow, orange, aqua, and sometimes green or violet fiber patch cables, you're not alone.