Grice on second-order vacuities

From online site, Stanford notes on 'unexistent objects', online:

"At least, this is one of the possible interpretations of what the object called “blue” is, according to MOTo. Alternatively, one might interpret the object blue as

ιx∀F(Fx ≡ B ⇒ F)

i.e., as

the object that has all and only those properties that are implied by the property of being blue (like being colored, for instance). It is difficult to decide whether Meinong, in the early version of his theory of objects, intended the object blue to be interpreted one way or the other. Since this question is of merely historical interest, we'll assume, for the sake of convenience, that according to MOTo the first interpretation is the correct one and leave the more complex interpretation for later."