BLUES

Neptune Blue

#39729C

RGB 57, 114, 156 · HSL 205°, 46%, 42% · CMYK 63, 27, 0, 39

Neptune Blue is #39729C in HEX — rgb(57, 114, 156), hsl(205°, 46%, 42%), cmyk(63%, 27%, 0%, 39%).

Neptune Blue pulls into the rich end of the blues spectrum — HSL 205°, 46%, 42%. The balanced saturation makes it confident without overpowering, 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#39729C

RGB57, 114, 156

HSL205°, 46%, 42%

HSV205°, 63%, 61%

CMYK63, 27, 0, 39

Decimal3764892

CSS RGBrgb(57, 114, 156)

CSS HSLhsl(205, 46%, 42%)

Paint Matches — this color across 16 brands

Behr

Neptune Blue 570D-6

Exact match

Benjamin Moore

Chicago 804

ΔE 1.6 · #41739D

Dulux

Naval S36G6

ΔE 1.7 · #41759F

Kilz

Triumph Blue RC280-01

ΔE 2.4 · #3F73A0

PPG

Blue Oasis 1158-6

ΔE 4.1 · #296D93

Vista Paint

Zenith C-646

ΔE 4.3 · #49789D

Sherwin-Williams

Danube SW6803

ΔE 4.7 · #2377A2

Hallman-Lindsay

Zenith 647

ΔE 4.7 · #497A9F

Dunn-Edwards

Rainy Lake DE5852

ΔE 4.9 · #3F6C8F

Valspar

Burbling Brook 4007-8C

ΔE 5.7 · #5175A1

RAL

Distant Blue 5023

ΔE 7.4 · #49678D

Kobra

Blue 29

ΔE 9.3 · #1882B4

Farrow & Ball

Pitch Blue 220

ΔE 12.8 · #636E8F

IKEA

IKEA128 128

ΔE 13.7 · #4A72B0

Dutch Boy

Ocean Blue D-6743

ΔE 19.7 · #4C6A74

Colorhouse

Dream .06 Dream-06

ΔE 22.2 · #0E707B

Light Reflectance & Undertone

Light Reflectance Value (LRV)

15/100

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

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

#39729C

#9C633A

Analogous

#3A9C94

#39729C

#3A429C

Triadic

#39729C

#9C3A73

#739C3A

Split-Complementary

#39729C

#9C3A42

#9C943A

Tetradic

#39729C

#943A9C

#9C633A

#429C3A

Monochromatic

#11212D

#254A65

#39729C

#5F9AC4

#97BDD8

Rectangle

#39729C

#633A9C

#9C633A

#739C3A

Compound

#39729C

#3A429C

#9C633A

#9C943A

Variations

Lighter

#5292BF

#84ACC9

#BBCEDC

Darker

#2C5D7F

#1D4059

#102534

Saturation

#5C6E7A

#3A739C

#1D78B9

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

5.17:1

vs Black

4.06:1

AA Large

Deuteranopia

#39729C

#54689D

Original → Simulated

Protanopia

#39729C

#6B6B97

Original → Simulated

Tritanopia

#39729C

#327973

Original → Simulated

Color Psychology

Focused · Cooling

Neptune 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

#6A8290

Warm Bulb 2700K

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

#39729C

Daylight 5500K

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

#5787B4

Cool Bulb 6500K

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

Pairs With

#E9EBEC

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.

#7F5537

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: #39729C;

CSS — background

background-color: #39729C;

CSS Variable

--color-neptune-blue: #39729C;

Tailwind v3 — config

colors: { 'neptune-blue': '#39729C' }

Tailwind — arbitrary

bg-[#39729C] text-[#39729C]

SCSS

$neptune-blue: #39729C;

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#40729C · ΔE 1.5

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#2474A3 · ΔE 4.2

Nile Blue

#4E719A · ΔE 5.2

Old Glory

#396998 · ΔE 5.5

Finley Blue

#4580A8 · ΔE 5.7

Bellbottom Blues

#386B8C · ΔE 5.9

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#00719C · ΔE 6.2

Seaport Blue

#006EA1 · ΔE 7.1

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 #39729C?

#39729C is Neptune Blue, a mid-tone blue with a cool undertone.

Is #39729C warm or cool?

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

What rooms work best with Neptune Blue?

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

What colors pair well with Neptune Blue?

Neptune 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 Neptune Blue?

You can download Neptune 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 Neptune Blue?

The hex code is #39729C. In RGB it's 57, 114, 156, and in HSL it's 205°, 46%, 42%.

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