RAL Classic color

RAL 6004 Blue green #1F3A3D

RAL 6004 Blue green is shown here as #1F3A3D, a widely published sRGB approximation of the printed swatch. It is a dark grayish teal in the neutral family. In OKLCH it sits at lightness 0.328, chroma 0.033 and hue 204.8°. The nearest CSS named color is darkslategray (#2F4F4F), ΔE2000 7.0 away.

Relative luminance
0.0365
OKLCH L · C · h
0.328 · 0.033 · 204.8
Best text
White 12.13:1
Hue family
Neutral

#1F3A3D color codes

HEX
#1F3A3D
RGB
rgb(31, 58, 61)
HSL
hsl(186, 33%, 18%)
OKLCH
oklch(0.328 0.033 204.8)
OKLab
oklab(0.328 -0.030 -0.014)
CIELAB (D65)
L* 22.49, a* -9.32, b* -5.09
XYZ (D65)
X 2.92, Y 3.65, Z 4.97
CMYK (naive)
cmyk(49%, 5%, 0%, 76%)

CIELAB and XYZ use the D65 white point; CSS lab() uses D50, so paste the OKLCH or HEX value into stylesheets. CMYK here is a plain formula with no press profile.

RAL and RAL Classic are trademarks of RAL gGmbH, which this site is not affiliated with. The sRGB value is an approximation of the printed swatch; check a physical RAL color card before you specify a paint.

Legibility

Contrast: is #1F3A3D accessible?

White text on it reaches 12.13:1, passing AAA. Black text fails at 1.73:1.

WCAG 2 gives the same ratio whichever color is the text; APCA does not, so its Lc changes sign and size with polarity.

Open the Contrast System
  • Black text on it

    1.73:1

    • AA fails
    • AA large fails
    • AAA fails
    • APCA Lc 0
  • White text on it

    12.13:1

    • AA passes
    • AA large passes
    • AAA passes
    • APCA Lc −101
  • As text on black

    1.73:1

    • AA fails
    • AA large fails
    • AAA fails
    • APCA Lc 0
  • As text on white

    12.13:1

    • AA passes
    • AA large passes
    • AAA passes
    • APCA Lc +97

Nearest versions that pass 4.5:1

  • For text on white

    #1F3A3D 12.13:1

    It already reaches 12.13:1 on white, so no change is needed.

  • For text on black

    #5D7A7D 4.54:1

    Lightening its OKLCH lightness from 0.33 to 0.56 reaches 4.54:1 on black, keeping the hue.

Checking another pair? Use the Contrast Checker.

Studio

Adjust #1F3A3D live

Move lightness, chroma and hue in OKLCH, or drag on the map. The map is every lightness and chroma at the current hue: sRGB inside the solid area, Display P3 out to the dashed line.

The studio needs JavaScript.

Scale

Shades and tints of #1F3A3D

Eleven OKLCH lightness steps at this hue, each with its contrast against white and black. #1F3A3D sits at step 800.

  1. 50#E2FBFE
    White
    1.07
    Black
    19.46
  2. 100#D7F1F4
    White
    1.18
    Black
    17.77
  3. 200#C2DEE1
    White
    1.41
    Black
    14.82
  4. 300#A7C4C7
    White
    1.84
    Black
    11.36
  5. 400#8AA8AB
    White
    2.53
    Black
    8.26
  6. 500#6F8C90
    White
    3.60
    Black
    5.82
  7. 600#587578
    White
    4.96
    Black
    4.23
  8. 700#435E61
    White
    6.97
    Black
    3.01
  9. 800This color#1F3A3D
    White
    12.13
    Black
    1.73
  10. 900#172D2F
    White
    14.45
    Black
    1.45
  11. 950#07191B
    White
    18.04
    Black
    1.16

Under each step, white and black text on it; a bold figure passes 4.5:1.

Gamut

How vivid #1F3A3D can get

At its lightness and hue, sRGB reaches OKLCH chroma 0.056; #1F3A3D uses 59% of it. Display P3, which many recent phones and laptops show, reaches 0.075 there: 34% more.

0.00.20.40.60.80.20.40.60.8 460480500520540560580600620
  • sRGB
  • Display P3
  • Rec. 2020
  • Dominant wavelength
OKLCH chroma
0.033
sRGB edge
0.056
Display P3 edge
0.075
Rec. 2020 edge
0.124
Dominant wavelength
489 nm
Excitation purity
23%
Chromaticity
x 0.2531, y 0.3167
  • This color#1F3A3D
  • Most vivid in sRGB#003D42
  • Most vivid in Display P3oklch(0.328 0.075 204.8)

On a screen without Display P3 the last tile shows the sRGB edge instead.

Use the wider color where screens show it
.accent {
  color: #1f3a3d;
}
@media (color-gamut: p3) {
  .accent { color: color(display-p3 0 0.2425 0.2734); }
}

Mixing

Mixing #1F3A3D

Each row is the same mix worked out in a different space, with the halfway color at its end. sRGB, which older CSS gradients use, can sag gray or dark in the middle; OKLab keeps the lightness steps even; OKLCH holds chroma and hue as it goes.

White #FFFFFF

  • sRGB50%#8F9D9E
  • OKLab50%#889798
  • OKLCH50%#889798

Black #000000

  • sRGB50%#101D1F
  • OKLab50%#061012
  • OKLCH50%#061012

Its complement #452E2C

  • sRGB50%#323435
  • OKLab50%#353535
  • OKLCH50%#363245
In CSS
/* A gradient and a mix, worked out in OKLCH */
background: linear-gradient(in oklch, #1f3a3d, white);
color: color-mix(in oklch, #1f3a3d 50%, white);

In use

#1F3A3D in an interface

A button, a link, a heading, a focused field, an icon and a chart line in this color, on a light page and a dark one. Each check is a WCAG 2 contrast minimum: 1.4.3 for text, 1.4.11 for the rest.

Light page

  • Button labelText, 4.5:112.13:1 Passes
  • Link and body-size textText, 4.5:112.13:1 Passes
  • Large headingLarge text, 3:112.13:1 Passes
  • Icons, borders and focus ringsNon-text, 3:112.13:1 Passes

Dark page

  • Button labelText, 4.5:112.13:1 Passes
  • Link and body-size textText, 4.5:11.54:1 Fails
  • Large headingLarge text, 3:11.54:1 Fails
  • Icons, borders and focus ringsNon-text, 3:11.54:1 Fails

For text on this page, the nearest shade that passes is #668386 4.59:1

Color vision

How #1F3A3D looks with color blindness

Deuteranopia changes it most, ΔE2000 11.9; tritanopia changes it least, 4.8.

Simulated with Machado et al. (2009) at full severity, in linear light.

Simulate a whole page What each type sees
  • Protanopia

    No working red (long-wavelength) cones

    #36383D ΔE2000 11.1

    Distinct

    Reads as dark gray

  • Deuteranopia

    No working green (medium-wavelength) cones

    #31343D ΔE2000 11.9

    Distinct

    Reads as dark gray

  • Tritanopia

    No working blue (short-wavelength) cones

    #113C3B ΔE2000 4.8

    Close match

    Reads as dark grayish teal

  • Achromatopsia

    No cone color vision; lightness only

    #363636 ΔE2000 11.1

    Distinct

    Reads as dark gray

Pairing check

A near-neutral has no complementary hue to pair with, so tell it apart from neighboring grays by lightness contrast alone.

Harmony

Color harmonies for #1F3A3D

Its complement is #452E2C, a dark grayish brown.

Hue rotations in OKLCH, mapped into sRGB by trimming chroma so hue and lightness stay put.

Open the Harmony Studio
  • Base#1F3A3D
  • Complement#452E2C

Complementary

Open in Harmony Studio
  • −30°#223B34
  • Base#1F3A3D
  • +30°#243844
  • Base#1F3A3D
  • +120°#3E2F3F
  • +240°#3D3421
  • Base#1F3A3D
  • +150°#432E36
  • +210°#433024

Split-complementary

Open in Harmony Studio

Code

Design tokens

Ready-to-paste tokens in six formats. Rename them to fit your system.

CSS custom property

:root {
  --color-ral-6004: #1f3a3d;
}

Tailwind config

// tailwind.config.js
module.exports = {
  theme: {
    extend: {
      colors: {
        'ral-6004': '#1f3a3d',
      },
    },
  },
};

Tailwind v4 theme

/* app.css — Tailwind CSS v4 */
@import "tailwindcss";

@theme {
  --color-ral-6004: oklch(0.328 0.033 204.8);
}

Design token (W3C DTCG)

{
  "color": {
    "ral-6004": {
      "$type": "color",
      "$value": {
        "colorSpace": "srgb",
        "components": [0.1216, 0.2275, 0.2392],
        "hex": "#1f3a3d"
      },
      "$description": "RAL 6004 Blue green (approximate sRGB)"
    }
  }
}

SwiftUI color

import SwiftUI

enum Palette {
    static let ral6004 = Color(.sRGB, red: 0.122, green: 0.227, blue: 0.239, opacity: 1)
}

Jetpack Compose color

import androidx.compose.ui.graphics.Color

object Palette {
    val Ral6004 = Color(0xFF1F3A3D)
}

Matches

The nearest match in each system

The closest CSS name, Tailwind shade, RAL Classic paint and Crayola crayon by ΔE2000; under 2 is hard to tell apart side by side. RAL and Crayola values approximate physical colors.

Tools

Open #1F3A3D in the tools

Each opens over this page. More colors live in the Color Library, and every color page is listed on the hub.