 What is CAT 6 RJ45 wiring? RJ45 is the standard connection for structured cabling. This is for categories from CAT 5E through to CAT 6A. CAT 7 and above still take the basis of the RJ45 connector and add additional termination points. However, they all still plug in together. The connector consists of eight core colors separated into four pairs which are twisted together. The color groups are blue, green, orange and brown. These match throughout the cable, module and patch panel. Therefore regardless of the category of cable transmission still occurs.