Grammar & Showing

In the Philosophical Remarks Wittgenstein writes,

If I could describe the point of grammatical conventions by saying they are made necessary by certain properties of the colours (say), then that would make the conventions superfluous, since in that case I would be able to say precisely that which the conventions exclude my saying. Conversely, if the conventions were necessary, i.e. if certain combinations of words had to be excluded as nonsensical, then for that very reason I cannot cite a property of colours that makes the convention necessary, since it would then be conceivable that the colours should not have this property, and I could only express that by violating the conventions.

Isn't this the saying/showing distinction applied to grammar?

Wittgenstein & Phenomenology

On the first page of Philosophical Remarks, Wittgenstein writes that

Physics differs from phenomenology in that it is concerned to establish laws. Phenomenology only establishes possibilities. Thus, phenomenology would be the grammar of the description of those facts on which physics builds its theories.

This remark is similar to section 90 of Philosophical Investigations:

We feel as if we had to penetrate phenomena: our investigation however is directed not towards phenomena, but, as one might say, towards the 'possibilities' of phenomena. We remind ourselves, that is to say, of the kind of statement that we make about phenomena.

If Philosophical Investigations is directed towards possibilities of phenomena (why is 'possibilities' in quotation marks), is it phenomenological in Wittgenstein's sense?