RJ45 Color Codes and Everything Else You Need to Know

Oct. 25, 2023
The RJ45 has standard color codes used in most typical installations.

What is an RJ45?

The RJ45 is a type of connector which describes both male RJ45 plugs and female RJ45 sockets. The male plugs are also called modular connectors and are typically on the end of Ethernet cables. The female sockets or jacks are usually embedded in the device that is mounted or hooked up to a fixed wall panel. In many environments, RJ45 connectors are generally used for plugging an internet-enabled device into hardware like servers, modems, and routers.

An RJ45 connector is a modular, eight-position, eight-pin connector used for terminating Cat5e or Cat6 twisted-pair cable. The connector is mechanically keyed, meaning that there’s an extra tab made to prevent the connector from being paired with socket standards that may seem similar but are not compatible electrically and it also prevents accidental disconnection.

For the RJ45 to work correctly, the eight individual Ethernet cabling wires have to be inserted into the right pinout areas on the male connector which is either with the T568A or T568B wiring scheme. Both schemes have their own unique color coding which leads to two different types of connectivity.

Standard color codes for the RJ45

To know which color code is needed, the correct pinout must be identified. The two most popular pinouts are T568A and T568B.

The T568B is used in the United States for twisted-pair structured cabling. The four wires it has each pair being a different color. When it comes to the order of green and orange pairs the T568A is where it differs from the T568B. If one is not certain of which of the two color code schemes to use, it is recommended to choose the T568B.

What’s the difference between the T568A and T568B?

While the colors used might be the same for both the RJ45 T568A and T568B the colors come in a different order for each one.

The application of the T568B comes in its ability to connect HUBs, switches, and other devices, while the T568A is utilized to connect dual computers.

When it comes to compatibility, the T568A is compatible with one or two pairs of USOC wiring schemes. On the other hand, the T568B is compatible with only a single pair of USOC wiring schemes. However, the T568B can match the AT&T 258A color code.

About the Author

Serena Aburahma | Associate Editor

Serena Aburahma is a recent graduate from California State University, Northridge receiving a B.A. in Honor's English Literature. Serena has several years of writing and SEO experience, which include creating a variety of content ranging from cars and insurance to video games and pop culture. Much like the content Serena's written about, her interests vary as well, from writing poetry and stories and advocating for mental health, to playing video games, traveling, and reading.

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