I agree, it is a bit misleading.
I pretty much derived the clue description from here: https://logic.puzzlebaron.com/how-to-solve-a-logic-puzzle.php?t=neither-nor-clue...
I see if I can come up with a clue that is more clear. I think "There are no square or blue sculptures" is missing the hint, that squares also cannot be blue. ;)
The complete clue would be something like: "Neither squares nor sculptures are blue" AND "Sculptures are not square".