GREYS

Swollen Sky

#66677C

RGB 102, 103, 124 · HSL 237°, 10%, 44% · CMYK 18, 17, 0, 51

Swollen Sky is #66677C in HEX — rgb(102, 103, 124), hsl(237°, 10%, 44%), cmyk(18%, 17%, 0%, 51%).

Swollen Sky pulls into the rich end of the greys spectrum — HSL 237°, 10%, 44%. The neutral saturation makes it near-neutral and forgiving, and the hue reads cool. In interior projects it shines on walls, soft furniture, hard surfaces — as the project's quiet backbone. Reads best alongside white trim, natural wood, brass, soft black accents.

Color Codes

HEX#66677C

RGB102, 103, 124

HSL237°, 10%, 44%

HSV237°, 18%, 49%

CMYK18, 17, 0, 51

Decimal6711164

CSS RGBrgb(102, 103, 124)

CSS HSLhsl(237, 10%, 44%)

Paint Matches — this color across 16 brands

Dulux

Swollen Sky S42C6

Exact match

Dunn-Edwards

Graphite DE5936

ΔE 1 · #656579

Behr

Nostalgic UL240-2

ΔE 2.8 · #646B7E

Vista Paint

Purple Pansies K-41

ΔE 2.9 · #6B6678

PPG

Great Grape 1169-6

ΔE 3 · #6B6D85

Sherwin-Williams

Mesmerize SW6544

ΔE 3 · #5D657B

RAL

Pearl Black Berry 4012

ΔE 3.2 · #6C6881

Benjamin Moore

Blue 1435 · CC-900

ΔE 3.4 · #5D6375

Valspar

Dark Night 4003-4C

ΔE 3.7 · #5E6576

Hallman-Lindsay

Grapes Of Wrath 1284

ΔE 4.3 · #65627D

IKEA

IKEA156 156

ΔE 6.7 · #676973

Kilz

Wine Hour RA290-02

ΔE 6.7 · #5E5871

Farrow & Ball

Pitch Blue 220

ΔE 8 · #636E8F

Colorhouse

Wool .06 Wool-06

ΔE 11.9 · #485761

Dutch Boy

Ocean Blue D-6743

ΔE 12.9 · #4C6A74

Kobra

Grey 42

ΔE 17.2 · #889099

Light Reflectance & Undertone

Light Reflectance Value (LRV)

14/100

Dark

0 · DarkLight · 100

Soaks up light and feels moody and intimate. Great for studies, dining rooms and accent walls; pair with ample lighting.

Undertone

TemperatureCool MasstoneBlue UndertoneViolet

A near-neutral with a subtle cool violet undertone — it will pick up colour from surrounding surfaces and shift noticeably under different light.

Color Theory

Complementary

#66677C

#7B7A65

Analogous

#65717B

#66677C

#6F657B

Triadic

#66677C

#7B6566

#667B65

Split-Complementary

#66677C

#7B6F65

#717B65

Tetradic

#66677C

#7B6571

#7B7A65

#657B6F

Monochromatic

#202027

#434351

#66677C

#8C8DA1

#B6B7C3

Rectangle

#66677C

#7A657B

#7B7A65

#667B65

Compound

#66677C

#6F657B

#7B7A65

#717B65

Variations

Lighter

#818298

#A2A3B1

#CACAD1

Darker

#505163

#373844

#202028

Saturation

#6D6D74

#65667B

#3239AE

Interior Use

Best Rooms

living rooms, bedrooms, bathrooms

Best Uses

walls, soft furniture, hard surfaces

Pairs With

white trim, natural wood, brass, soft black accents

Accessibility (WCAG)

vs White

5.53:1

vs Black

3.80:1

AA Large

Deuteranopia

#66677C

#63697C

Original → Simulated

Protanopia

#66677C

#67677A

Original → Simulated

Tritanopia

#66677C

#646B68

Original → Simulated

Color Psychology

Quiet · Versatile

Swollen Sky gets out of the way so the architecture and the people in the room do the work. The right neutral is never a default — it reads warm or cool, dusty or sharp depending on its undertone, and that undertone is what makes or breaks the room.

SymbolismBalance, sophistication, calm

PersonalityAdaptable, considered, timeless

versatileneutraltimelessbackdroptrimwall

How it looks under different light

#8C7A78

Warm Bulb 2700K

Incandescent / soft white LED — pulls colour toward yellow/amber.

#66677C

Daylight 5500K

Midday natural light or daylight-spec LED — closest to the paint chip.

#797F9C

Cool Bulb 6500K

Cool white LED / overcast daylight — pulls colour toward blue.

Pairs With

#EAEAEB

Trim

Matched off-white

Same hue at 92% lightness — trim reads coordinated, not stark.

#F7F7F7

Ceiling

Whisper tint

Near-white with a hint of the hero's undertone — ceiling feels intentional.

#777548

Accent

Complementary punch

Hue +180°, slightly muted for paint vs. screen — use on a door, frame, or single piece.

#574738

Floor

Walnut neutral

Warm mid-brown grounds the scheme regardless of hero hue.

Paint Info

Brand · Product Line

Benjamin Moore / Regal Select Interior

Recommended Finishes

Eggshell (walls) · Pearl (trim) · Matte (ceiling)

Eggshell hides imperfections on main walls while keeping the color rich; pearl on trim adds subtle sheen and easier cleaning; flat matte on ceilings prevents glare.

Best Surfaces

Primary walls · Cabinetry · Doors · Mouldings

Coverage & Dry Time

Typical coverage 350-400 sq ft per gallon over a primed surface.

Touch-dry in ~1 hour. Recoat after 4 hours. Full cure 7-14 days.

Primer

Standard primer is adequate.

Application Tip

Use a 9" microfiber roller on walls and a 2.5" angled sash brush for trim cuts. Two coats minimum for even depth.

Paint Calculator

Wall area (m²)

Coats

Coverage (m² / L)

You'll need

4.0 litres

1.06 US gallons · room for one touch-up coat. Buy slightly more to ensure single-batch match.

Code Snippets

CSS — color

color: #66677C;

CSS — background

background-color: #66677C;

CSS Variable

--color-swollen-sky: #66677C;

Tailwind v3 — config

colors: { 'swollen-sky': '#66677C' }

Tailwind — arbitrary

bg-[#66677C] text-[#66677C]

SCSS

$swollen-sky: #66677C;

Similar Colors

French Violet

#696D86 · ΔE 3.4

Blue Gaspe

#5C6274 · ΔE 3.7

Nightfall Sky

#6F6578 · ΔE 4.4

Amethyst Shadow

#6E7182 · ΔE 4.6

Blue Heron

#5C6A85 · ΔE 5.6

Pinot Grigio Grape

#6F6177 · ΔE 6.0

Andes Summit

#586471 · ΔE 6.9

Wild Mulberry

#6B5E6B · ΔE 7.7

Built by DSGN.HOUSE Updated 2026

Our color tools run on our own catalogue of 26,000+ real paint colors across 16 brands — Benjamin Moore, Sherwin-Williams, Behr, Dulux, RAL and more — with the color math (HSL and CIELAB matching) computed in-house, not scraped from summaries. Every color you pick maps to a real, buyable paint with its code, so what you see here you can actually take to the store. We review and update these tools and their data regularly.

Created by Denis Kataev, founder of DSGN.HOUSE — a software engineer and digital entrepreneur building professional color-design tools for everyone.

Frequently Asked Questions

What color is #66677C?

#66677C is Swollen Sky, a mid-tone grey with a cool undertone.

Is #66677C warm or cool?

Swollen Sky reads cool, which influences how it interacts with surrounding tones and natural light.

What rooms work best with Swollen Sky?

Swollen Sky works well in living rooms, bedrooms, bathrooms. Designers typically use it for walls, soft furniture, hard surfaces.

What colors pair well with Swollen Sky?

Swollen Sky pairs naturally with white trim, natural wood, brass, soft black accents. Its complementary color is also a strong contrast option for accents.

Where can I download Swollen Sky?

You can download Swollen Sky on DSGN.HOUSE in 15 designer formats including CSS gradient, Figma, Procreate swatches, Tailwind config, Adobe ASE, SVG, and 4K wallpapers — all free.

What's the hex code for Swollen Sky?

The hex code is #66677C. In RGB it's 102, 103, 124, and in HSL it's 237°, 10%, 44%.

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