For full context, see here.
It is in paragraph 2, example:
=> "Someone looks for a shirt of different size and being the same color"
I interpreted it as the continuative form of です, but in this case, at least from a conceptual perspective, it could just as well be the particle で.
"Someone looks for a shirt of different size with the same color."
That's why I wanted to ask for confirmation whether I'm right or not.