A programmable RJ45 jack is disclosed. In some examples, the RJ45 jack may be configured to emit a user-defined color at the presence of a user-selectable data-link characteristic. In some examples, any number of programmable RJ45 jacks may be included within a device, such as an ethernet switch. A configuration database describing a relationship between data-link characteristics and colors may be downloaded to a device that includes the programmable RJ45 jack.