You're right about the form coming forward without the color fighting for attention. I shoot film landscapes, mostly dusk work, and I've had that same realization with gradient skies, sometimes stripping one variable away shows you what the light was actually doing. That anemone holds its structure well in mono.

You stripped away the one thing most photographers would lean on, and the flower holds. That delicate form you mentioned, it reads stronger without the pink pulling attention. I notice that choice in my own work too, when texture or structure needs to speak first. The anemone has real presence here.