RGB lighting Power Options

[Kev.uk]

Hi peeps I'm in abit of a situation I have RGB lighting strips under my desk and around monitor powered by mains socket which have to manually turn off n on, I'm looking for a solution to get them to power on when pc starts meaning most likely will have to be USB but doesn't usb ports only give 5V ? I know u can buy usb relays to mains, Would a mains powered usb be an easier way around would it work the same way ? Thanks