"Stay a little more sanitary for longer"??? I surmise that means they are using some polyester or acrylic material instead of natural cotton or wool, that does not absorb moisture because it's a synthetic.
"Dark in color so as to not show dirt and wear as much"??? Are Bombas SERIOUS??? I live in a major metropolitan city that has an extreme homeless crisis. I pass by homeless people all the time. No homeless person is concerned about how much dirt and wear any of the clothing they are able to scrounge and find has. Sorry, that is just a crock of **** that they even say that. Homeless people live moment to moment. From one meal to the next. They aren't counting in days how much longer one pair of socks looks less worn than another pair.
So, it is likely that Bombas makes cheap dollar store equivalent, synthetic, black socks that they give the homeless. Socks they don't even sell to customers.
Basically Bombas is a very high end sock company that uses giving away socks to homeless as their advertising instead of just saying they are charging a lot of money for socks period. Yes, it's true the give away socks, and they never do state or show the pairs they donate are of an equivalent quality. In fact, they make a point to show those socks are different.