T568A and T568B Wiring Schemes -- What's the Difference? Based on TIA/EIA-568-B.1-2001, the T568A and T568B wiring schemes define the pinout, or order of connections, for wires in eight-pin modular connector plugs and jacks. The only difference between T568A and T568B is that pairs 2 and 3 (orange and green) are swapped. What is the difference between T568A & T568B - Acuity T568A and T568B are the two color codes used for wiring eight-position RJ45 modular plugs. Both are allowed under the ANSI/TIA/EIA wiring standards. The only difference between the two color codes is that the orange and green pairs are interchanged.