If I had known that the blue ones felt better, in terms of quality, I wouldn't have bought so many, or rather any black ones at all, they feel ragged.
The blue ones feel firmer.
The elastic band is different on the blue ones, I have just compared them again. Unfortunately, there was only ever one or two packs in stock, so of course I checked the blue ones, then it took a relatively long time until I had my contingent together for the first new textile wash and thought the black ones were the same. That was a mistake.
for another variant: night blue, S
A little short on the legs
for another variant: night blue, XL
Very good quality for this price and comfortable to wear