BLUES

Subterranean River

#1F3B4D

RGB 31, 59, 77 · HSL 203°, 43%, 21% · CMYK 60, 23, 0, 70

Subterranean River is #1F3B4D in HEX — rgb(31, 59, 77), hsl(203°, 43%, 21%), cmyk(60%, 23%, 0%, 70%).

Subterranean River pulls into the deep end of the blues spectrum — HSL 203°, 43%, 21%. 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#1F3B4D

RGB31, 59, 77

HSL203°, 43%, 21%

HSV203°, 60%, 30%

CMYK60, 23, 0, 70

Decimal2046797

CSS RGBrgb(31, 59, 77)

CSS HSLhsl(203, 43%, 21%)

Paint Matches — this color across 16 brands

Dulux

Harpoon S36C9

ΔE 2.4 · #273C4C

Behr

New Navy Blue BXC-26

ΔE 3.4 · #264156

Sherwin-Williams

In the Navy SW9178

ΔE 3.7 · #283849

Benjamin Moore

North CC-932

ΔE 3.8 · #2C3C4D

Vista Paint

Blazer Blue K-152

ΔE 4.8 · #243A52

RAL

Ocean Blue 5020

ΔE 5.5 · #1D334A

Dunn-Edwards

Deep Ocean DEA135

ΔE 7 · #2A4B5F

Hallman-Lindsay

Star-studded 620

ΔE 7 · #32425A

Kobra

Blue 31

ΔE 7.8 · #334059

PPG

Sailor's Coat 1153-7

ΔE 7.9 · #334B58

Valspar

Indigo Streamer 4010-4

ΔE 9.9 · #404C5B

Kilz

Fountain Pen RC100-02

ΔE 10.4 · #354A67

Farrow & Ball

Hague Blue 30

ΔE 10.9 · #3D4E57

IKEA

IKEA122 122

ΔE 13.1 · #3A5170

Colorhouse

Nourish .06 Nourish-06

ΔE 13.4 · #313536

Dutch Boy

Royal Blue D-6740

ΔE 13.5 · #1D375C

Light Reflectance & Undertone

Light Reflectance Value (LRV)

4/100

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

#1F3B4D

#4D301F

Analogous

#1F4D47

#1F3B4D

#1F244D

Triadic

#1F3B4D

#4D1F3B

#3B4D1F

Split-Complementary

#1F3B4D

#4D1F24

#4D471F

Tetradic

#1F3B4D

#471F4D

#4D301F

#244D1F

Monochromatic

#070E12

#091116

#1F3B4D

#346583

#4C8FB8

Rectangle

#1F3B4D

#301F4D

#4D301F

#3B4D1F

Compound

#1F3B4D

#1F244D

#4D301F

#4D471F

Variations

Lighter

#356786

#5A90B2

#A3BDCE

Darker

#172F3E

#10212B

#09131A

Saturation

#2F373C

#1F3B4D

#0F3E5C

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

11.73:1

AAA

vs Black

1.79:1

Fail

Deuteranopia

#1F3B4D

#2D364E

Original → Simulated

Protanopia

#1F3B4D

#37374B

Original → Simulated

Tritanopia

#1F3B4D

#1D3E3B

Original → Simulated

Color Psychology

Focused · Cooling

Subterranean River 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

#575955

Warm Bulb 2700K

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

#1F3B4D

Daylight 5500K

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

#445E79

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.

#3F2A1D

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

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: #1F3B4D;

CSS — background

background-color: #1F3B4D;

CSS Variable

--color-subterranean-river: #1F3B4D;

Tailwind v3 — config

colors: { 'subterranean-river': '#1F3B4D' }

Tailwind — arbitrary

bg-[#1F3B4D] text-[#1F3B4D]

SCSS

$subterranean-river: #1F3B4D;

Similar Colors

North Sea

#2B3B4C · ΔE 3.7

Twilight

#254455 · ΔE 4.0

Hidden Sapphire

#023B4E · ΔE 5.1

Washington Blue

#304656 · ΔE 5.5

Deep Royal

#2F394B · ΔE 5.8

Marine Blue

#1D3E59 · ΔE 6.1

Old Navy

#2E3549 · ΔE 7.4

Teal

#144552 · 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 #1F3B4D?

#1F3B4D is Subterranean River, a deep blue with a cool undertone.

Is #1F3B4D warm or cool?

Subterranean River reads cool, which influences how it interacts with surrounding tones and natural light.

What rooms work best with Subterranean River?

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

What colors pair well with Subterranean River?

Subterranean River 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 Subterranean River?

You can download Subterranean River 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 Subterranean River?

The hex code is #1F3B4D. In RGB it's 31, 59, 77, and in HSL it's 203°, 43%, 21%.

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