EIA/TIA 568B is a standard for the pin arrangements of RJ-45 connectors on Unshielded Twisted Pair (UTP) wire.

The 568B standard was developed by AT&T under the name 258A.

568B Color Codes

Pin (Jack) Pin (Plug) Color Pair
1 8 White/Orange 2 – Tip
2 7 Orange 2 – Ring
3 6 White/Green 3 – Tip
4 5 Blue 1 – Ring
5 4 White/Blue 1 – Tip
6 3 Green 3 – Ring
7 2 White Brown 4 – Tip
8 1 Brown 4 – Ring

Pin numbers are read left-to-right with the connector tab facing down.

568B vs. 568A

When installing additional wiring into an existing facility, it is usually best to determine which wiring standard is currently in use and conform to that standard.

The most prevalent standards are TIA/EIA 568A and EIS/TIA 568B.

When installing telephone wiring into a new facility, EIA/TIA 568A is the standard to utilize.