What do different USB colours mean?
Q
I’ve been told that USB ports are colour coded, with USB 3.0 being blue, and USB 2.0 black. I have USB sticks coloured blue, black and red. On my laptop computer I have three USB ports – two coloured black and one coloured blue. Is what I’ve been told correct? All of my USB sticks work in all of the ports on my laptop. Ronnie Williams
A
What you’ve been told has some truth to it, but it’s not necessarily true!
To explain, we must first say that the branding of the endless USB versions, sub-versions and speed protocols is almost impossible for mere mortals to unravel. Fortunately, the interface itself is blissfully simple to use, so most of the time this naming mess doesn’t matter: if you can plug a USB device into a USB socket, it’ll often work.
As a rule of thumb, a higher USB number generally means a faster interface. So, while it’s an oversimplification, a USB 3.0 socket should transfer stuff quicker than the USB 2 equivalent, while a USB 3.1 or 3.2 port will generally outperform a corresponding USB 3.0 socket. Note that we haven’t even mentioned the different socket shapes, such as the traditional, rectangular Type-a or the modern, smaller and reversible Type-c ( USB-C). There’s also USB 4.0 on the way – but let’s not further muddy these murky waters!
So, what of the colours? Well, the current formal specifications, maintained by the USB Implementers Forum ( www.usb.org), don’t mention colour. This means any socket (or plug) can be any colour – because officially the colour denotes nothing. However, confusingly, the original USB 3.0 specification did recommend blue plastic inserts, so many PC manufacturers followed and still follow this. This original recommendation also applied to the plugs of faster USB 3.0 devices, incidentally. Older, slower USB 2.0 Type-a sockets were traditionally black, so blue was a useful distinguishing characteristic.
The upshot is that the blue USB 3.0 socket is no longer an official standard, though it is often the colour used. So, the colour of your USB sticks could mean something or nothing. The blue one probably does mean a faster USB 3.0 device, but that’s not a certainty. The black one might mean slower USB 2.0 speeds, but it’s just as likely a USB 3.0 device made by a manufacturer that didn’t bother with a blue insert. And the red one? That’s just a style choice, to match the outer casing.