BLUES

North Sea Blue

#343D4C

RGB 52, 61, 76 · HSL 218°, 19%, 25% · CMYK 32, 20, 0, 70

North Sea Blue is #343D4C in HEX — rgb(52, 61, 76), hsl(218°, 19%, 25%), cmyk(32%, 20%, 0%, 70%).

North Sea Blue pulls into the deep end of the blues spectrum — HSL 218°, 19%, 25%. The neutral saturation makes it near-neutral and forgiving, 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#343D4C

RGB52, 61, 76

HSL218°, 19%, 25%

HSV218°, 32%, 30%

CMYK32, 20, 0, 70

Decimal3423564

CSS RGBrgb(52, 61, 76)

CSS HSLhsl(218, 19%, 25%)

Paint Matches — this color across 16 brands

Dulux

North Sea Blue S40C9

Exact match

Sherwin-Williams

Naval SW6244

ΔE 1.9 · #2F3D4C

Benjamin Moore

Deep 2061-10

ΔE 2.4 · #303A4C

Behr

Black Elegance N570-7

ΔE 2.7 · #3C3F4D

Dunn-Edwards

Old Mill DEA185

ΔE 2.9 · #343B4E

Vista Paint

Pantry Plum K-88

ΔE 3.3 · #3D3F4C

Valspar

Blue Coal 4011-3

ΔE 4.6 · #414450

PPG

Wright Midnight FLLW36

ΔE 5.9 · #404149

Hallman-Lindsay

Star-studded 620

ΔE 6.3 · #32425A

RAL

Slate Grey 7015

ΔE 6.4 · #434750

Kobra

Blue 31

ΔE 6.6 · #334059

Kilz

Night Magic RM230

ΔE 7.1 · #3C4348

IKEA

IKEA163 163

ΔE 7.4 · #423A45

Farrow & Ball

Hague Blue 30

ΔE 8.5 · #3D4E57

Colorhouse

Metal .06 Metal-06

ΔE 9.9 · #3F4647

Dutch Boy

Royal Blue D-6740

ΔE 15.3 · #1D375C

Light Reflectance & Undertone

Light Reflectance Value (LRV)

5/100

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

#343D4C

#4C4334

Analogous

#34494C

#343D4C

#37344C

Triadic

#343D4C

#4C343D

#3D4C34

Split-Complementary

#343D4C

#4C3734

#494C34

Tetradic

#343D4C

#4C3449

#4C4334

#344C37

Monochromatic

#0A0C0F

#15181E

#343D4C

#536179

#7686A2

Rectangle

#343D4C

#43344C

#4C4334

#3D4C34

Compound

#343D4C

#37344C

#4C4334

#494C34

Variations

Lighter

#536179

#7A879F

#B3BAC5

Darker

#29303D

#1C212A

#101319

Saturation

#3C3F43

#343D4C

#1A3666

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)

vs White

10.95:1

AAA

vs Black

1.92:1

Fail

Deuteranopia

#343D4C

#363C4C

Original → Simulated

Protanopia

#343D4C

#3C3C4A

Original → Simulated

Tritanopia

#343D4C

#33403E

Original → Simulated

Color Psychology

Focused · Cooling

North Sea Blue 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

#665A54

Warm Bulb 2700K

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

#343D4C

Daylight 5500K

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

#545F78

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.

#443A29

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: #343D4C;

CSS — background

background-color: #343D4C;

CSS Variable

--color-north-sea-blue: #343D4C;

Tailwind v3 — config

colors: { 'north-sea-blue': '#343D4C' }

Tailwind — arbitrary

bg-[#343D4C] text-[#343D4C]

SCSS

$north-sea-blue: #343D4C;

Similar Colors

Deep Royal

#2F394B · ΔE 2.7

North Sea

#2B3B4C · ΔE 3.0

Blackberry Punch

#3F4150 · ΔE 3.6

Polo Blue

#323A43 · ΔE 4.2

Old Navy

#2E3549 · ΔE 5.0

Deep Mulberry

#3C3845 · ΔE 5.5

Washington Blue

#304656 · ΔE 5.5

Evening Sky

#464956 · ΔE 6.3

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 #343D4C?

#343D4C is North Sea Blue, a deep blue with a cool undertone.

Is #343D4C warm or cool?

North Sea Blue reads cool, which influences how it interacts with surrounding tones and natural light.

What rooms work best with North Sea Blue?

North Sea Blue works well in bedrooms, bathrooms, home offices. Designers typically use it for main walls, ceilings, trim, cabinetry.

What colors pair well with North Sea Blue?

North Sea Blue 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 North Sea Blue?

You can download North Sea Blue 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 North Sea Blue?

The hex code is #343D4C. In RGB it's 52, 61, 76, and in HSL it's 218°, 19%, 25%.

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