I always assumed $10$ was pronounced "ten" regardless of whether it's binary, decimal, or another system, just like how 5 is "five" in all systems that the digit exists exists. But someone told me that, if it's not base-10, it should be pronounced "one-zero", and that "ten" is the name of the number, not the ordered group of digits. I see no reason why it should, as taking that logic to hexadecimal, a should be called "ten", b "eleven" and so on. To me, that sounds like it would create more confusion. However, I have nothing to support (or refute) my view (neither does he, so far).
So, what is it, really? Or is it personal preference?