Since the look and even gender of Noble Six was fully customizable you can say there is no “canon” look of B312 but when you think of him/her how do you imagine Noble Six?
I think of Noble Six as having all default armor, armor color of steel both primary and secondary and a gender of male. That is what I consider the “canon” B312 to be in my mind. You?
I imagined Noble 6 as a strong and noble Nord, with flowing blonde hair with braids at either end, and someone who fights scarabs and takes bullets to the knee in his spare time.
I pictured him as that guy who sits at the lunch table all alone because of his boring attitude.
> I think of Noble Six as having all default armor, armor color of steel both primary and secondary and a gender of male. That is what I consider the “canon” B312 to be in my mind. You?
this. i believe it is canon since: every picture (in stragety guides, xfinity posterboard, etc…) of Noble Six is this, every vidoc before Reach was released was this, every action figure of Noble Six is this, AND the firefight pic of Noble Six is this.
I imagined “Natalie-B312” to be somewhat of a more “humble” Starbuck (Captain Kara Thrace from Battlestar Galactica). Combat-wise, more or less, someone you wouldn’t care to share a dark alley with…especially if you’re on someone’s s**tlist at Naval Intelligence. 
I looked in the mirror and did my best tiger-face. GRRRR
> I imagined Noble 6 as a strong and noble Nord, with flowing blonde hair with braids at either end, and someone who fights scarabs and takes bullets to the knee in his spare time.
I used to be a Lone Wolf like you… then I took a Needle to the knee…