Coastal Grey vs Sleepy Blue
Coastal Grey is a Dulux color while Sleepy Blue comes from Sherwin-Williams. Hue-wise, Coastal Grey belongs to the blue-grey family and Sleepy Blue to the blue family. With LRVs of 56 and 58, they'll behave almost identically in terms of how much light they reflect back into a room. They share a cool quality — useful to know if you're layering them in the same space. With a ΔE of 1.8, the difference is subtle — you'd need them side by side to reliably tell them apart. Below you'll find 1 real-room photo comparison where both colors appear side by side, plus 5 simulated room previews.
Coastal Grey vs Sleepy Blue in Real Spaces
1 real room side by side. Coastal Grey and Sleepy Blue 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 two are close enough that the choice comes down to finer qualities — undertone, texture, what the color sits next to.
Color Details
Coastal Grey vs Sleepy Blue Simulated Comparison
5 simulated room previews — drag the slider on each to see Coastal Grey on one side and Sleepy Blue 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 Coastal Grey comparisons
See how Coastal Grey stacks up against other well-photographed colors across different brands and tones.
At LRV 69 vs 56, Ammonite is decisively the brighter choice.
White Dove reflects far more light (LRV 83 vs 56), opening up a space where Coastal Grey encloses it.
Coastal Grey reflects far more light (LRV 56 vs 6), opening up a space where Iron Ore encloses it.
A 4-point LRV gap (56 vs 52) makes Coastal Grey the marginally brighter of the two.
At LRV 56 vs 30, Coastal Grey is decisively the brighter choice.
Coastal Grey reads slightly lighter (LRV 56 vs 52), a gap that shows most in low-lit rooms.
A 4-point LRV gap (60 vs 56) makes Agreeable Gray the marginally brighter of the two.
With LRVs of 58 and 56, the two reflect almost the same amount of light.
Coastal Grey reflects far more light (LRV 56 vs 27), opening up a space where Denim Drift encloses it.
At LRV 56 vs 43, Coastal Grey is decisively the brighter choice.
At LRV 56 vs 4, Coastal Grey is decisively the brighter choice.
With LRVs of 56 and 55, the two reflect almost the same amount of light.
Coastal Grey reflects far more light (LRV 56 vs 13), opening up a space where Bancha encloses it.
Coastal Grey reflects far more light (LRV 56 vs 44), opening up a space where Hardwick White encloses it.
At LRV 84 vs 56, Pure White is decisively the brighter choice.
At LRV 56 vs 21, Coastal Grey is decisively the brighter choice.
Balboa Mist reads slightly lighter (LRV 66 vs 56), a gap that shows most in low-lit rooms.
Shoji White reflects far more light (LRV 74 vs 56), opening up a space where Coastal Grey encloses it.
Snowbound reflects far more light (LRV 83 vs 56), opening up a space where Coastal Grey encloses it.
A 5-point LRV gap (56 vs 51) makes Coastal Grey the marginally brighter of the two.
Coastal Grey reflects far more light (LRV 56 vs 12), opening up a space where Pewter Green encloses it.
Coastal Grey reflects far more light (LRV 56 vs 8), opening up a space where Duck Green encloses it.
Skimming Stone reflects far more light (LRV 68 vs 56), opening up a space where Coastal Grey encloses it.
At LRV 56 vs 41, Coastal Grey is decisively the brighter choice.
Coastal Grey reflects far more light (LRV 56 vs 12), opening up a space where Vintage Vogue encloses it.
Coastal Grey reads slightly lighter (LRV 56 vs 45), a gap that shows most in low-lit rooms.
At LRV 56 vs 31, Coastal Grey is decisively the brighter choice.