Mermaid Sea vs Ionian
Mermaid Sea is a Behr color while Ionian comes from Sherwin-Williams. These are both blues, so the question isn't which hue to choose — it's where within blue to land. At LRV 20 vs 13, Ionian will read as the brighter of the two — a 7-point gap that matters most in north-facing or low-light rooms. The tonal difference — Mermaid Sea's green and blue character against Ionian's cool — becomes most visible against white trim or in morning light. At ΔE 3.9, the difference is perceptible but not dramatic — the two can work harmoniously in the same space. Below you'll find 1 real-room photo comparison where both colors appear side by side, plus 5 simulated room previews.
Mermaid Sea vs Ionian in Real Spaces
1 real room side by side. Mermaid Sea and Ionian are close enough that the difference can be hard to judge from a chip alone — these photos show how each reads at scale, across different spaces and lighting conditions.
Bathroom
Bathrooms amplify color — the enclosed space and reflective surfaces make what reads subtle elsewhere feel more present here. The brightness difference is modest but present — Ionian gives the walls a little more lift.
Color Details
Mermaid Sea vs Ionian Simulated Comparison
5 simulated room previews — drag the slider on each to see Mermaid Sea on one side and Ionian on the other.
Digital color is approximate. These simulations are generated from the manufacturer's hex values and overlaid on grayscale room photos — your screen's calibration, brightness, and viewing angle all affect how they render. Before committing to either color, test physical samples in your own space under the light you actually live with.
More Mermaid Sea comparisons
See how Mermaid Sea stacks up against other well-photographed colors across different brands and tones.
