The blue USB-A ports can deliver up to 900ma. USB C can deliver 1.5A on a single lane or 3A with multi-lane, or higher if using "power delivery" standards.
Simon's quite correct about 900mA for blue ports, I inadvertently checked the "power delivery" specification for power capability, not the main specification, without realising it was a special case. In my defence, at 631 pages the USB-3.1 specification is 1.5 times the size of the BIAB manual and the power delivery specification is a further 381 pages. The base USB-2 spec is another 650 pages, then there are the protocol specs and the connector specs and ....
Where I last worked, when I reported a delay because something on USB wasn't yet working properly (A Windows 7 bug as it turned out) our sales director's response was "It's USB, you just plug it in and it works! What's the problem?".
Idiot!