If the computer has only black color USB sockets and not blue one means it is 2.0 only and not 3.0.
A USB 3.0 HDD with Blue USB plug will work without any problem on a USB 2.0 computer, but works only at 2.0 speed. There is no need to install any USB 3.0 drivers on the computer.
USB 3.0 drivers will get installed and work only if there is a USB 3.0 controller with blue USB 3.0 sockets in a computer.
USB 3.0 has 5 extra pins in the connector. They are the recessed ones just above the 4 protruding ones in the pic. Connectors are not always blue. My laptop's are black & the recesses for the extra 5 contacts are on all the USB's even the 2.0's, but those have no contacts. If you shine a flashlight into the connector & look very closely, you can see the electrical contacts, if they exist. This is the ONLY way to tell if it is truly USB 3.0.
I have posted the image of USB 3.0 and USB 2.0 sockets on my Toshiba laptop.
The image shows blue socket with USB 3.0 interface. The symbol above USB 3.0 interface shows SS and a flash symbol between the USB symbol. SS for Super Speed. The blue socket shows 4 USB 2.0 contacts in the rear and 5 USB 3.0 contacts in the front. This socket works for both USB 3.0 and USB 2.0 plugs.
Whereas the black socket is USB 2.0 only and shows a standard USB symbol above it. This socket shows only the 4 USB 2.0 contacts. This socket though works with USB 3.0 devices, operates only at USB 2.0 speeds.
There is also a similar socket available with some laptops. This is called power eSATA. This socket is a combination of eSATA and USB 2.0. This socket can be used for either USB 2.0 cable or eSATA cable.
A separate cable is also available to make use eSATA and USB 2.0 simultaneously.
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USB 3.0 sockets are typically blue, and they're probably that color to distinguish them from USB 2.0. Search the web and look at any USB 3.0 socket or cable and they'll be blue - usb 3.0 socket - Google Search. The ones on my motherboard are blue, the ones on my PC case, as well as the supporting USB 3.0 cables, are blue.
USB 3.0: What Is It and Do You Want It? - Opinion - Trusted Reviews
Typically, yes, you are correct. But not always, as I was attempting to point out. My HP laptop is not blue & is not labeled in any manner, either HS or SS, but it is 3.0 & functions as such with my USB 3.0 hard drive & USB 3.0 flash drive. It has 4 USB ports & only 1 is 3.0. Some almost identical models don't have the 3.0 port, even HP's documentation is incorrect regarding this model. See my System Specs.
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