According to TIA/EIA-598, the standard 4 core fiber optic cable color code begins with blue for the first fiber, followed by orange for the second, green for the third, and brown for the fourth. By adopting the TIA/EIA‑598C standard, you gain a universal “language” of colors that speeds identification, reduces miswiring, and enhances safety. This guide covers everything you need to know about 4 core fiber, including its internal structure, TIA standard color coding, and how to choose the right type. This color-coding standard ensures consistency, safety, and reliability throughout manufacturing, installation, and maintenance. By following it. This Applications Note addresses Corning Optical Communications' identification scheme for optical fiber cables.