Valve determination

[Spinkboy]

So see the pictures below. This is on a 2019 Cougar 29RKS

I assume RED is for connecting to city water (hose) and supply water from there?

I assume Green is for filling tank?

I assume Black is for flushing black water? and can do that with the supply valves above.

Sorry for the dumb questions but no walk thru and my last RV just had a hose connection and the gravity tank fill.

Thanks

Spink