First monotub — is this healthy mycelium or should I be worried?

Two weeks into my first oyster monotub. Colonization looks nearly complete — lovely dense white rhizomorphic growth across the top. But there is one small patch near the corner that looks a touch grey and I am paranoid.

Temps holding at 72F, FAE via holes with poly-fil. Do I wait for a full flush or is that grey patch a red flag?

Adding: no off smells, still smells pleasantly mushroomy.

Grey with no green/black spores and no sour smell is very often just older, slightly hydrated mycelium or early primordia, not contam. Watch it for 24-48h. If it stays fuzzy-white and starts pinning, you are golden.