Cosmic Blue vs Just Walnut
Where Cosmic Blue belongs to Behr's range, Just Walnut is a Dulux color. Hue-wise, Cosmic Blue belongs to the blue family and Just Walnut to the beige-greige family. Just Walnut (LRV 72) reflects noticeably more light than Cosmic Blue (LRV 47), a difference of 25 points that becomes especially apparent in rooms with limited natural light. Cosmic Blue runs blue while Just Walnut is decidedly warm, which means they'll respond very differently to warm vs cool light sources. With a ΔE of 22.6, the contrast is hard to miss. These aren't variations on a theme — they're two different answers to the same question. Below you'll find 5 real-room photo comparisons where both colors appear side by side, plus 5 simulated room previews.
Cosmic Blue vs Just Walnut in Real Spaces
5 real rooms side by side. Seeing Cosmic Blue and Just Walnut in actual rooms makes the difference concrete; browse the spaces below to get a feel for how each color lives on a wall.
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 LRV gap is large enough that Just Walnut will make the room feel meaningfully brighter than Cosmic Blue would.
Bedroom
The context that matters most in a bedroom is how a color reads under a bedside lamp at night, not under noon daylight. Just Walnut reflects noticeably more light off the walls, making the space read more open than Cosmic Blue.
Kitchen
In a kitchen, colors are seen under bright task lighting that amplifies undertones — what reads neutral elsewhere can show its hand here. Just Walnut reflects noticeably more light off the walls, making the space read more open than Cosmic Blue.
Bathroom
Bathrooms are one of the few spaces where you're genuinely enclosed by the paint color, which makes the choice between these two more consequential. Just Walnut reflects noticeably more light off the walls, making the space read more open than Cosmic Blue.
Kitchen Cabinets
Kitchen cabinets are constantly compared against adjacent materials, which means subtle differences between these two become much more visible. Just Walnut reflects noticeably more light off the walls, making the space read more open than Cosmic Blue.
Color Details
Cosmic Blue vs Just Walnut Simulated Comparison
5 simulated room previews — drag the slider on each to see Cosmic Blue on one side and Just Walnut 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 Cosmic Blue comparisons
See how Cosmic Blue stacks up against other well-photographed colors across different brands and tones.
At LRV 83 vs 47, White Dove is decisively the brighter choice.
Ammonite reflects far more light (LRV 69 vs 47), opening up a space where Cosmic Blue encloses it.
At LRV 47 vs 6, Cosmic Blue is decisively the brighter choice.
Purbeck Stone reads slightly lighter (LRV 52 vs 47), a gap that shows most in low-lit rooms.
Cosmic Blue reflects far more light (LRV 47 vs 30), opening up a space where Evergreen Fog encloses it.
A 5-point LRV gap (52 vs 47) makes Mizzle the marginally brighter of the two.
Agreeable Gray reflects far more light (LRV 60 vs 47), opening up a space where Cosmic Blue encloses it.
A 11-point LRV gap (58 vs 47) makes Accessible Beige the marginally brighter of the two.
At LRV 47 vs 27, Cosmic Blue is decisively the brighter choice.
Cosmic Blue reads slightly lighter (LRV 47 vs 43), a gap that shows most in low-lit rooms.
Cosmic Blue reflects far more light (LRV 47 vs 4), opening up a space where Naval encloses it.
A 8-point LRV gap (55 vs 47) makes Tranquil Dawn the marginally brighter of the two.
At LRV 47 vs 13, Cosmic Blue is decisively the brighter choice.
Their light reflectance is nearly identical (LRV 47 vs 44), so neither reads brighter in a room.
Pure White reflects far more light (LRV 84 vs 47), opening up a space where Cosmic Blue encloses it.
Cosmic Blue reflects far more light (LRV 47 vs 21), opening up a space where Artichoke encloses it.
At LRV 66 vs 47, Balboa Mist is decisively the brighter choice.
At LRV 74 vs 47, Shoji White is decisively the brighter choice.
At LRV 83 vs 47, Snowbound is decisively the brighter choice.
At LRV 47 vs 12, Cosmic Blue is decisively the brighter choice.
At LRV 68 vs 47, Skimming Stone is decisively the brighter choice.
Cosmic Blue reads slightly lighter (LRV 47 vs 41), a gap that shows most in low-lit rooms.
Calamine reflects far more light (LRV 68 vs 47), opening up a space where Cosmic Blue encloses it.
Cosmic Blue reflects far more light (LRV 47 vs 25), opening up a space where Treron encloses it.
At LRV 47 vs 12, Cosmic Blue is decisively the brighter choice.
Their light reflectance is nearly identical (LRV 47 vs 45), so neither reads brighter in a room.
Cosmic Blue reflects far more light (LRV 47 vs 31), opening up a space where Pale Green encloses it.
Cosmic Blue reflects far more light (LRV 47 vs 7), opening up a space where Pine Needle encloses it.
Cosmic Blue reflects far more light (LRV 47 vs 24), opening up a space where Cement grey encloses it.
Guilford Green reads slightly lighter (LRV 57 vs 47), a gap that shows most in low-lit rooms.