Under the TIA/EIA-598-C standard, the universal 12-color sequence is: 1-Blue, 2-Orange, 3-Green, 4-Brown, 5-Slate (Gray), 6-White, 7-Red, 8-Black, 9-Yellow, 10-Violet, 11-Rose, and 12-Aqua. This sequence repeats for cables with more than 12 fibers. Cable Structure The 12 core. Prysmian uses the US industry standard repeating 12-color sequence. (FOA) was founded in 1995 to help develop the workforce to build the fiber optic networks to support a rapid expansion in communications and the Internet. Hexatronic offers cables with color code systems according to all interna ional and national standards and for all types of fiber opti such as a tube, ribbon, yarn wrapped bundle or other types of bundle.