Should it be non-restrictive?

Question

I posted something related to this, but I doubt something is strange. I understand sentences like 'red juice turned blue' can be true, but I think, when it comes to a stative verb, 'red juice was blue' is a nonsense other than 'juice, which is red, was blue' becauae juice cannot be both red and blue at the same time. Moreover, we don't say, even though a candy, which is blue, was red, 'I stepped on the blue candy,' but 'I stepped on the red candy.'