Harlequin Blue vs Cosmos
Where Harlequin Blue belongs to Benjamin Moore's range, Cosmos is a Sherwin-Williams color. These are both blues, so the question isn't which hue to choose — it's where within blue to land. They have nearly identical light reflectance values (38 vs 38), so they'll read as similarly Medium in most lighting conditions. Harlequin Blue runs blue while Cosmos is decidedly cool, which means they'll respond very differently to warm vs cool light sources. At ΔE 2.7, these are close — the kind of difference that matters when choosing between them, but doesn't read strongly in a finished room. Below you'll find 3 real-room photo comparisons where both colors appear side by side, plus 5 simulated room previews.
Harlequin Blue vs Cosmos in Real Spaces
3 real rooms side by side. Harlequin Blue and Cosmos 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.
Living Room
In a living room, color works across both daylight and evening light — the same wall can read very differently at noon and at 8pm. The two are close enough that the choice comes down to finer qualities — undertone, texture, what the color sits next to.
Bedroom
The context that matters most in a bedroom is how a color reads under a bedside lamp at night, not under noon daylight. At this scale the difference is subtle — you'd need them side by side, as shown here, to reliably tell them apart.
House
Seen across an entire facade, subtle tonal differences become pronounced. What reads as nearly the same on a chip often reads as clearly different at scale. At this scale the difference is subtle — you'd need them side by side, as shown here, to reliably tell them apart.
Color Details
Harlequin Blue vs Cosmos Simulated Comparison
5 simulated room previews — drag the slider on each to see Harlequin Blue on one side and Cosmos 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 Harlequin Blue comparisons
See how Harlequin Blue stacks up against other well-photographed colors across different brands and tones.
At LRV 69 vs 38, Ammonite is decisively the brighter choice.
White Dove reflects far more light (LRV 83 vs 38), opening up a space where Harlequin Blue encloses it.
Harlequin Blue reflects far more light (LRV 38 vs 6), opening up a space where Iron Ore encloses it.
At LRV 52 vs 38, Purbeck Stone is decisively the brighter choice.
A 8-point LRV gap (38 vs 30) makes Harlequin Blue the marginally brighter of the two.
Mizzle reflects far more light (LRV 52 vs 38), opening up a space where Harlequin Blue encloses it.
At LRV 60 vs 38, Agreeable Gray is decisively the brighter choice.
Accessible Beige reflects far more light (LRV 58 vs 38), opening up a space where Harlequin Blue encloses it.
Harlequin Blue reads slightly lighter (LRV 38 vs 27), a gap that shows most in low-lit rooms.
A 5-point LRV gap (43 vs 38) makes French Gray the marginally brighter of the two.
At LRV 38 vs 4, Harlequin Blue is decisively the brighter choice.
Tranquil Dawn reflects far more light (LRV 55 vs 38), opening up a space where Harlequin Blue encloses it.
Harlequin Blue reflects far more light (LRV 38 vs 13), opening up a space where Bancha encloses it.
Hardwick White reads slightly lighter (LRV 44 vs 38), a gap that shows most in low-lit rooms.
At LRV 84 vs 38, Pure White is decisively the brighter choice.
At LRV 38 vs 21, Harlequin Blue is decisively the brighter choice.
Balboa Mist reflects far more light (LRV 66 vs 38), opening up a space where Harlequin Blue encloses it.
Shoji White reflects far more light (LRV 74 vs 38), opening up a space where Harlequin Blue encloses it.
Snowbound reflects far more light (LRV 83 vs 38), opening up a space where Harlequin Blue encloses it.
At LRV 51 vs 38, Pigeon is decisively the brighter choice.
Harlequin Blue reflects far more light (LRV 38 vs 12), opening up a space where Pewter Green encloses it.
Harlequin Blue reflects far more light (LRV 38 vs 8), opening up a space where Duck Green encloses it.
Skimming Stone reflects far more light (LRV 68 vs 38), opening up a space where Harlequin Blue encloses it.
Their light reflectance is nearly identical (LRV 41 vs 38), so neither reads brighter in a room.
Harlequin Blue reflects far more light (LRV 38 vs 12), opening up a space where Vintage Vogue encloses it.
Saybrook Sage reads slightly lighter (LRV 45 vs 38), a gap that shows most in low-lit rooms.
A 7-point LRV gap (38 vs 31) makes Harlequin Blue the marginally brighter of the two.