Coastal Plain vs Marine

Both are Sherwin-Williams colors. These are both green-greys, so the question isn't which hue to choose — it's where within green-grey to land. With LRVs of 37 and 36, they'll behave almost identically in terms of how much light they reflect back into a room. The tonal difference — Coastal Plain's neutral character against Marine's cool — becomes most visible against white trim or in morning light. At ΔE 6.4, the difference is perceptible but not dramatic — the two can work harmoniously in the same space. Below, 5 simulated room previews show how each color reads at scale — real-room photos will be added as they become available.