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#1f3f39

a deep, soft cyan · cool · closest name: Dark Slate Gray

RGB
31, 63, 57
HSL
169°, 34%, 18%
CMYK
51, 0, 10, 75
Luminance
0.0414

At a glance

Every number on this page in one read: what #1f3f39 is made of, how bright it looks, and which way it leans.

Hex
#1f3f39
Hue
169°
cyan
Saturation
34%
soft
Lightness
18%
deep
Brightness
25%
HSV value
Perceived
21%
weighted brightness
Luminance
0.0414
WCAG relative
Temperature
Cool
82/100 cool
Color family
Cyan
Tone
Soft
Best ink
White
11.49:1
Closest name
Dark Slate Gray
ΔE2000 6.4
Where it sits
Hue169° of 360°
Saturation34%
Lightness18%
Temperature
Warm ← → Cool82% cool

Reads cool. Warm and cool siblings keep the same lightness, so you can swap one in without redoing your contrast maths.

Every format

HEX#1f3f39
RGBrgb(31, 63, 57)
HSLhsl(169, 34%, 18%)
CMYKcmyk(51%, 0%, 10%, 75%)
LABlab(24.1 -13.6 0.0)
LCHlch(24.1 13.6 180.0)
OKLCHoklch(0.341 0.040 180.3)
Decimal2047801
Display P3color(display-p3 0.122 0.247 0.224)

Copy-ready code

/* CSS */
color: #1f3f39;
background-color: #1f3f39;
/* Tailwind (arbitrary) */
class="text-[#1f3f39] bg-[#1f3f39]"
/* SCSS */
$brand: #1f3f39;
/* SwiftUI */
Color(red: 0.122, green: 0.247, blue: 0.224)
/* Android */
Color.parseColor("#1f3f39")
/* Flutter */
Color(0xFF1F3F39)
/* Python / OpenCV (BGR) */
(57, 63, 31)

Best text color

Only one of black and white can be right. This is the one, with the number that proves it.

Readable at a glance#ffffff on #1f3f39 · 11.49:1
Use #ffffffAAA at every size.
Aa
White text · 11.49:1 · recommended
AA pass · AA large pass · AAA pass
Aa
Black text · 1.83:1
AA fail · AA large fail · AAA fail
Reading the other direction: #1f3f39 as text scores 11.49:1 on white and 1.83:1 on black.

Accessibility — WCAG contrast

Aa
#1f3f39 on white: 11.49:1
AA ✓ pass · AA-large · AAA
Aa
#1f3f39 on black: 1.83:1
AA ✗ fail · AA-large · AAA
true color
protanopia · #3D3C39
deuteranopia · #37383A
tritanopia · #12403D

Color scale — 50 to 950

A Tailwind-shaped ramp built around this exact hex. #1f3f39 is pinned to step 950; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#F5F9F9
#ECF4F2
#D4E8E4
#B4DAD3
#8EC7BD
#69B5A7
#51A494
#43897C
#366D63
#2A5049
#1f3f39
Base = 950Lightest = 50 · #F5F9F9Darkest = 950 · #1f3f39
:root {
  --brand-50: #F5F9F9;
  --brand-100: #ECF4F2;
  --brand-200: #D4E8E4;
  --brand-300: #B4DAD3;
  --brand-400: #8EC7BD;
  --brand-500: #69B5A7;
  --brand-600: #51A494;
  --brand-700: #43897C;
  --brand-800: #366D63;
  --brand-900: #2A5049;
  --brand-950: #1f3f39;
  --brand: #1f3f39;
  --brand-ink: #ffffff;
}

Colors that work with #1f3f39

Not a palette — a role sheet. Each swatch answers one question you will hit while building the component.

Text on it#ffffff
White wins here
Surface#F5FAF9
Tinted page background
Border#C8E4DF
Hairlines and dividers
Muted text#4C9A8B
Captions on the surface
Accent#411D2D
Second voice, not a rival
Dark variant#2A554D
Hover, pressed, headers
Light variant#EEF7F5
Selected rows, tints
Dark surface#142421
Dark-mode background
Light mode
Everything in its place

Surface, border, heading and body all derive from this one hue, so the screen stays coherent without a second palette.

Primary actionSecondaryBadge
Dark mode
Same hue, inverted

Lightness flips, hue holds. The accent stays the anchor in both themes.

Primary actionSecondaryAccent

How to use #1f3f39

Derived from its contrast, chroma and lightness — not from taste.

Works well for
  • Body text and links on white
  • Charts, tags and secondary surfaces
  • Headers, footers and dark-mode surfaces
  • Brand accents, badges and data highlights
Use with care
  • Text on black or near-black surfaces
  • Black text placed on it
  • Thin strokes and 1px borders — they disappear on light UI
  • Pairing with a same-lightness hue — edges vibrate

Similar colors

One move away from this hex in each direction. Every swatch is its own page.

Color relationships

The wheel positions with their names attached, so you can grab the one you actually need.

Complementary#3F1F25
Analogous left#1F3F29
Analogous right#1F353F
Split-complement 1#3F1F35
Split-complement 2#3F291F
Triadic 1#391F3F
Triadic 2#3F391F
Tetradic#291F3F

RGB percentages

Red12.2%
Green24.7%
Blue22.4%

CMYK percentages

Cyan50.8%
Magenta0.0%
Yellow9.5%
Key (black)75.3%

Color previews

#1f3f39 text on a black background

contrast 1.83:1

Card sample

#1f3f39 text on a white background

contrast 11.49:1

Card sample

CSS3 live lab

Text font color

The quick brown fox

color: #1f3f39;
Background color
Panel with #1f3f39 background
background-color: #1f3f39;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #1f3f39;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(31, 63, 57, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(31, 63, 57, 0.45);
Border & gradient
Gradient panel
border: 3px solid #1f3f39;
background: linear-gradient(135deg, #1f3f39, #1F303F);

Monochromatic scale

Palettes built from #1f3f39

Shades — darker

Tints — lighter

Color harmonies

Nearest named colors

Ranked with CIEDE2000 across all 139 CSS keywords. Under ΔE 2 the eye stops telling them apart; over ΔE 10 they are plainly different colors.

#1f3f39 in the real world

Where a color in this family tends to land, and the interface roles it is usually asked to play.

Industries
TechnologyTravelHealthcareMedia
Common UI roles
ButtonsLinksFocus statesCharts
Print note

Converts to four-color process without much drama. Proof it anyway.

#1f3f39, answered

What color is #1f3f39?

#1f3f39 is a deep soft cyan, closest to Dark Slate Gray (ΔE2000 6.4). It sits at 169° on the hue wheel with 34% saturation and 18% lightness, which reads as cool.

What is the RGB value of #1f3f39?

rgb(31, 63, 57) — 31 red, 63 green and 57 blue out of 255, or 12.2% / 24.7% / 22.4% by channel.

Is #1f3f39 a light or a dark color?

It is a dark color. Relative luminance is 0.0414 and perceived brightness is 21%, so white text on it reaches 11.49:1.

Should I use black or white text on #1f3f39?

White. It scores 11.49:1 against #1f3f39, versus 1.83:1 for black — AAA at any size.

What is the complementary color of #1f3f39?

#3F1F25 sits directly opposite on the wheel. Softer options are the split-complements #3F1F35 and #3F291F, which give the same contrast with far less vibration.

What colors go well with #1f3f39?

For interface work: #F5FAF9 as the surface, #C8E4DF for borders, #4C9A8B for secondary text, #411D2D as an accent and #2A554D for hover and pressed states. For a palette, the analogous pair #1F3F29 and #1F353F stays calm, while #3F1F25 is the loudest partner.

What is #1f3f39 in CMYK for printing?

cmyk(51%, 0%, 10%, 75%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #1f3f39 warm or cool?

Cool — it scores 82 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #1F3F2D; nudged cooler, #1E3A40.

Work with #1f3f39 in the Color Lab