There are four wires inside the “universal serial bus,” or USB typically made up of red, green, white, and black. These wires each have a matching signal or function. Identifying the positive and negative terminals is crucial when working with them.
In general, the red wire is a positive power connection with 5 volts of DC electricity. The ground (negative) power wire is the black wire (similar to almost all electronic devices). Another”positive” transmission data cable is the white wire. Lastly, the “negative” transmission data cable is the green one.
While there are a total of two positive and negative wires, each has different functionalities.
In this article, we’ll be going into more detail on these wires.
What Does Each of the USB Cable’s Four Wires Do?
One of the most widely used ports and communication protocols on devices is the USB or Universal Serial Bus. The purpose of USB was to regulate the ports that computer accessories like printers and keyboards connected to. You may find port variations on gadgets like cellphones, scanners, cameras, and game controllers that communicate with hosts. (1)

Opening up a USB cable reveals four distinct USB wire colors: red and black for power, white and green for data transmission, and so on. The positive wire, which carries 5 volts, is red; the negative wire, often known as the ground wire, is black. There is a pinout scheme for each type of USB connection; these are the tiny metal strips inside the connector that are used to reach each of these cables and their functions.
Colors of USB Cables and What They Indicate
Wire Color | Indication |
Red Wire | The positive power cable applies a DC power of 5 volts. |
Black Wire | The ground or a negative power wire. |
White Wire | The positive data transmission wire. |
Green Wire | The negative data transmission wire. |
Other USB Cable Wire Color Specifications
In some USB cords, you can find different wire color combinations, including orange, blue, white, and green.
Identifying which are positive or negative wires in this color scheme is different. In this instance, you should check the table below:
Wire Color | Indication |
Orange Wire | The positive power cable applies DC power of 5 volts. |
White Wire | The ground or a negative power wire. |
Blue Wire | The negative data transmission wire. |
Green Wire | The positive data transmission wire. |
USB Cable Types
There are various USB types, and the USB cord protocol determines how quickly it can transfer data. For instance, a USB 2.0 port can carry data up to 480 Mbps, whereas a USB 3.1 Gen 2 port can do so at 10 Mbps. You may use the chart below to understand the speed and features of each USB type:
USB Type | Can It Play Videos? | Is It Able to Deliver Power? | Data Transfer Speed |
USB 1.1 | No | No | 12 Mbps. |
USB 2.0 | No | Yes | 480 Mbps. |
USB 3.0 | Yes | Yes | 5 Gbps. |
USB 3.1 | Yes | Yes | 10 Gbps. |
FAQs

What Distinguishes a USB-C From a Regular USB?
When compared to USB-A, which can only handle up to 2.5 watts and 5 volts, USB-C can now comfortably handle 100 watts and 20 volts for larger devices. Pass-through charging—basically a USB hub that powers laptops and charges other devices simultaneously—is one of these useful advantages.
Are the Green and White Lines Significant?
The positive-negative wires are the most crucial cables. Knowing what color these electrical power pathways are is crucial because they are required to power your equipment.
Can a USB Cable be Split and Joined?
You can make your own USB cables by cutting and splicing existing ones to the length and connector style you need. The only tools required for the process are a wire cutter and electrical tape, though a soldering iron and heat shrink tubing can be used to improve cable quality. (2)
Take a look at some of our related articles below.
- How to tell negative and positive wire
- Is white wire positive or negative
- What is the blue wire on a ceiling fan
References
(1) computer accessories – https://www.newegg.com/Computer-Accessories/Category/ID-1
(2) USB – https://www.lifewire.com/universal-serial-bus-usb-2626039