BLUES

Petrol Slumber

#243640

RGB 36, 54, 64 · HSL 201°, 28%, 20% · CMYK 44, 16, 0, 75

Petrol Slumber is #243640 in HEX — rgb(36, 54, 64), hsl(201°, 28%, 20%), cmyk(44%, 16%, 0%, 75%).

Petrol Slumber pulls into the deep end of the blues spectrum — HSL 201°, 28%, 20%. The muted saturation makes it quiet but present, and the hue reads cool. In interior projects it shines on bedrooms, bathrooms, home offices — for calm, focused environments. Reads best alongside warm white trim, oak or walnut, brass or matte black hardware.

Color Codes

HEX#243640
RGB36, 54, 64
HSL201°, 28%, 20%
HSV201°, 44%, 25%
CMYK44, 16, 0, 75
Decimal2373184
CSS RGBrgb(36, 54, 64)
CSS HSLhsl(201, 28%, 20%)

Paint Matches — this color across 16 brands

Dulux

Precision S35B9

ΔE 2.5 · #2C3A44

Sherwin-Williams

Dark Night SW6237

ΔE 2.6 · #23383F

Behr

Night Shade 740F-7

ΔE 3.1 · #243A41

Vista Paint

In the Navy K-800

ΔE 4.1 · #313B45

RAL

Green Blue 5001

ΔE 4.6 · #1F3438

Benjamin Moore

Polo 2062-10

ΔE 4.8 · #333B44

Hallman-Lindsay

Octavius 522

ΔE 7.5 · #38393F

Colorhouse

Nourish .06 Nourish-06

ΔE 7.8 · #313536

Kilz

Night Magic RM230

ΔE 8.3 · #3C4348

Dunn-Edwards

Old Mill DEA185

ΔE 8.4 · #343B4E

PPG

Midnight Hour 1038-7

ΔE 8.7 · #3B484F

Valspar

Twilight Purple 4010-2

ΔE 9.3 · #3E3B46

Kobra

Black 44

ΔE 10 · #383737

IKEA

IKEA186 186

ΔE 10.1 · #302F2F

Farrow & Ball

Hague Blue 30

ΔE 10.6 · #3D4E57

Dutch Boy

Dark Green D-6751

ΔE 16.2 · #214136

Light Reflectance & Undertone

Light Reflectance Value (LRV)

3/100

Very Dark

0 · DarkLight · 100

Absorbs almost all light — dramatic and cocooning. Needs strong artificial lighting and works best as an accent or in well-lit rooms.

Undertone

TemperatureCool MasstoneBlue UndertoneViolet

Reads as a cool blue with a violet undertone showing through, especially in daylight. Pair trim and adjacent colours to either calm or amplify that undertone.

Color Theory

Complementary

#243640
#412F25

Analogous

#25413D
#243640
#252941

Triadic

#243640
#412537
#374125

Split-Complementary

#243640
#412529
#413D25

Tetradic

#243640
#3D2541
#412F25
#294125

Monochromatic

#090E10
#090E10
#243640
#406172
#5C8AA3

Rectangle

#243640
#2F2541
#412F25
#374125

Compound

#243640
#252941
#412F25
#413D25

Variations

Lighter

#426476
#678DA2
#AABCC6

Darker

#1D2C35
#131F25
#0B1216

Saturation

#2F3437
#253741
#123D54

Interior Use

Best Rooms

bedrooms, bathrooms, home offices

Best Uses

main walls, ceilings, trim, cabinetry

Pairs With

warm white trim, oak or walnut, brass or matte black hardware

Accessibility (WCAG)

Aa

vs White

12.52:1

AAA

Aa

vs Black

1.68:1

Fail

Deuteranopia

#243640
#2D3240

Original → Simulated

Protanopia

#243640
#33333F

Original → Simulated

Tritanopia

#243640
#233736

Original → Simulated

Color Psychology

Focused · Cooling

Petrol Slumber lowers the temperature of a room — useful in south-facing rooms that overheat visually, and in home offices where you want a clear head. Pair with warm wood and brass to keep it from reading clinical.

SymbolismTrust, depth, stability
PersonalityClear-headed, dependable, contemplative
focustrustcalmofficebedroomdepth

How it looks under different light

#5A554B

Warm Bulb 2700K

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

#243640

Daylight 5500K

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

#485A6F

Cool Bulb 6500K

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

Pairs With

#EAEBEC

Trim

Matched off-white

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

#F7F7F8

Ceiling

Whisper tint

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

#392A22

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 / Aura Interior (for richer color depth in deep tones)

Recommended Finishes

Matte (walls) · Pearl (trim) · Satin (doors)

Deep colors look best in matte — gloss exaggerates surface flaws. Reserve subtle sheen for trim, doors, and high-touch areas.

Best Surfaces

Accent walls · Doors · Cabinetry · Built-ins

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

Tinted primer in a similar value is highly recommended — saves a coat and prevents the wall colour from washing the surface.

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

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: #243640;
CSS — background 
background-color: #243640;
CSS Variable 
--color-petrol-slumber: #243640;
Tailwind v3 — config 
colors: { 'petrol-slumber': '#243640' }
Tailwind — arbitrary 
bg-[#243640] text-[#243640]
SCSS 
$petrol-slumber: #243640;

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#323A43 · ΔE 4.5

North Sea

#2B3B4C · ΔE 5.5

After Midnight

#33383E · ΔE 5.7

Soot

#373C41 · ΔE 6.8

Deep Royal

#2F394B · ΔE 6.8

Pacific Sea Teal

#274043 · ΔE 6.9

Black Knight

#303536 · ΔE 7.5

Salamander

#2F3E3E · ΔE 7.6
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 #243640?

#243640 is Petrol Slumber, a deep blue with a cool undertone.

Is #243640 warm or cool?

Petrol Slumber reads cool, which influences how it interacts with surrounding tones and natural light.

What rooms work best with Petrol Slumber?

Petrol Slumber works well in bedrooms, bathrooms, home offices. Designers typically use it for main walls, ceilings, trim, cabinetry.

What colors pair well with Petrol Slumber?

Petrol Slumber pairs naturally with warm white trim, oak or walnut, brass or matte black hardware. Its complementary color is also a strong contrast option for accents.

Where can I download Petrol Slumber?

You can download Petrol Slumber 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 Petrol Slumber?

The hex code is #243640. In RGB it's 36, 54, 64, and in HSL it's 201°, 28%, 20%.

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