An optical fiber cable includes pairs of transmission lines having length extensions and color coding to facilitate cable system assembly. Each transmission line is preferably constructed from unitary fibers including a P-type fiber and an N-type fiber with the length extensions of the same P-type and N-type fiber at each end respectively. The P-type fiber and the N-type fiber are preferably colored differently to indicate transmission direction. The P-type fiber and N-type fiber in one pair of transmission lines are preferably colored differently than the P-type fiber and N-type fiber in other pairs.