Yellow USB-A ports may charge devices after computers are switched off

Yellow USB-A ports often indicate an “Always On” charging feature, which can keep charging a device after a computer is switched off. The colour is only a manufacturer convention, though, so it does not guarantee the feature or tell you the port’s data speed.

Yellow ports are uncommon because they tend to appear on selected business or enterprise laptops, and manufacturers increasingly use battery symbols instead. Some computers require Always On charging to be enabled in the BIOS, and may only allow it while plugged into mains power. USB-IF recommends blue to distinguish USB 3.0 from USB 2.0, but colour guidance is not a mandate; check a label, the manual or the manufacturer’s specifications to confirm a port’s capabilities.