In reality, it’s easy to discern the physical differences between them. It is easy to tell the difference in their physical appearance. USB 2.0 Connectors is colored black or white inside and the USB 3.0 is colored blue inside. If you’re trying to know if you have a USB connection in your computer as well as USB flash drives are 2.0 or 3.0 You can tell these by their USB port’s color inside.