Yes, they could get black (look at paintings to see the frequency of black showing up as a color worn). Certainly that box of yarn isn't an EXCLUSIVE list of colors possible, simply one person's INCLUSIVE example.
black was expensive because it required frequent re-dyeing to keep it dark. This cost money for the garment had to be picked apart (the lining removed, buttons, trims, etc), dyed, and relined. This did, however, keep the garments going for a very long time. It was the lining that wore out first, and got stinky etc. So having the ability to take things apart to freshen them was great - for those that could pay for it.
For something like an arming coat - it was highly unlikely. The things that needed frequent washing were white or undyed. That said, clearly, some people were wearing garments that were colored as arming garments. Red seems to be frequent, as well as blue, but then these are easy colors to get.
Jess