RAL Classic color

RAL 5019 Capri blue #1B5583

RAL 5019 Capri blue is shown here as #1B5583, a widely published sRGB approximation of the printed swatch. It is a dark muted blue in the blue family. In OKLCH it sits at lightness 0.436, chroma 0.096 and hue 246.7°. The nearest CSS named color is royalblue (#4169E1), ΔE2000 14.1 away.

Relative luminance
0.0837
OKLCH L · C · h
0.436 · 0.096 · 246.7
Best text
White 7.85:1
Hue family
Blue
Inspect this color Check contrast

#1B5583 color codes

HEX
#1B5583
RGB
rgb(27, 85, 131)
HSL
hsl(207, 66%, 31%)
OKLCH
oklch(0.436 0.096 246.7)
OKLab
oklab(0.436 -0.038 -0.088)
CIELAB (D65)
L* 34.74, a* -1.45, b* -31.07
XYZ (D65)
X 7.80, Y 8.37, Z 22.67
CMYK (naive)
cmyk(79%, 35%, 0%, 49%)

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 #1B5583 accessible?

White text on it reaches 7.85:1, passing AAA. Black text fails at 2.67:1.

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

    2.67:1

    • AA fails
    • AA large fails
    • AAA fails
    • APCA Lc +17

  • White text on it

    7.85:1

    • AA passes
    • AA large passes
    • AAA passes
    • APCA Lc −91

  • As text on black

    2.67:1

    • AA fails
    • AA large fails
    • AAA fails
    • APCA Lc −15

  • As text on white

    7.85:1

    • AA passes
    • AA large passes
    • AAA passes
    • APCA Lc +86

Nearest versions that pass 4.5:1

  • For text on white

    #1B5583 7.85:1

    It already reaches 7.85:1 on white, so no change is needed.

  • For text on black

    #427AAA 4.59:1

    Lightening its OKLCH lightness from 0.44 to 0.56 reaches 4.59:1 on black, keeping the hue.

    Compare both in the Contrast System

Checking another pair? Use the Contrast Checker.

Studio

Adjust #1B5583 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 #1B5583

Eleven OKLCH lightness steps at this hue, each with its contrast against white and black. #1B5583 sits at step 700.

  1. 50#EDF6FF
    White
    1.09
    Black
    19.22
  2. 100#DBEEFF
    White
    1.18
    Black
    17.68
  3. 200#B7DCFF
    White
    1.42
    Black
    14.69
  4. 300#8EC4F5
    White
    1.84
    Black
    11.36
  5. 400#6FA7D9
    White
    2.55
    Black
    8.20
  6. 500#538BBD
    White
    3.62
    Black
    5.79
  7. 600#3C73A3
    White
    5.03
    Black
    4.17
  8. 700This color#1B5583
    White
    7.85
    Black
    2.67
  9. 800#0C436B
    White
    10.34
    Black
    2.03
  10. 900#002B4B
    White
    14.51
    Black
    1.44
  11. 950#00172C
    White
    18.12
    Black
    1.15

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

Gamut

How vivid #1B5583 can get

At its lightness and hue, sRGB reaches OKLCH chroma 0.114; #1B5583 uses 84% of it. Display P3, which many recent phones and laptops show, reaches 0.148 there: 30% more.

0.00.20.40.60.80.20.40.60.8 460480500520540560580600620
  • sRGB
  • Display P3
  • Rec. 2020
  • Dominant wavelength
OKLCH chroma
0.096
sRGB edge
0.114
Display P3 edge
0.148
Rec. 2020 edge
0.369
Dominant wavelength
478 nm
Excitation purity
52%
Chromaticity
x 0.2007, y 0.2155
  • This color#1B5583
  • Most vivid in sRGB#00558C
  • Most vivid in Display P3oklch(0.436 0.148 246.7)

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

Use the wider color where screens show it
.accent {
  color: #1b5583;
}
@media (color-gamut: p3) {
  .accent { color: color(display-p3 0 0.321 0.594); }
}

Mixing

Mixing #1B5583

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%#8DAAC1
  • OKLab50%#8CA7C1
  • OKLCH50%#8CA7C1

Black #000000

  • sRGB50%#0E2B42
  • OKLab50%#051C2F
  • OKLCH50%#051C2F

Its complement #744501

  • sRGB50%#484D42
  • OKLab50%#515151
  • OKLCH50%#12613B
In CSS
/* A gradient and a mix, worked out in OKLCH */
background: linear-gradient(in oklch, #1b5583, white);
color: color-mix(in oklch, #1b5583 50%, white);

In use

#1B5583 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, 4.5:17.85:1 Passes
  • Link and body-size textText, 4.5:17.85:1 Passes
  • Large headingLarge text, 3:17.85:1 Passes
  • Icons, borders and focus ringsNon-text, 3:17.85:1 Passes

Dark page

  • Button labelText, 4.5:17.85:1 Passes
  • Link and body-size textText, 4.5:12.38:1 Fails
  • Large headingLarge text, 3:12.38:1 Fails
  • Icons, borders and focus ringsNon-text, 3:12.38:1 Fails

For text on this page, the nearest shade that passes is #4981B2 4.51:1

Color vision

How #1B5583 looks with color blindness

Achromatopsia changes it most, ΔE2000 18.3; deuteranopia changes it least, 6.1.

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

    #405785 ΔE2000 6.7

    Noticeable

    Reads as dark muted blue

  • Deuteranopia

    No working green (medium-wavelength) cones

    #314D82 ΔE2000 6.1

    Noticeable

    Reads as dark muted blue

  • Tritanopia

    No working blue (short-wavelength) cones

    #006066 ΔE2000 17.8

    Distinct

    Reads as dark muted teal

  • Achromatopsia

    No cone color vision; lightness only

    #525252 ΔE2000 18.3

    Distinct

    Reads as dark gray

Pairing check

Checked against its complement, #744501. Their lightness contrast is only 1.03:1, so where hue collapses, add a label, icon or pattern.

VisionThe pairΔE2000Verdict
Normal vision#1B5583 · #74450141.2Stays distinct
Protanopia#405785 · #54490042.5Stays distinct
Deuteranopia#314D82 · #5F540345.6Stays distinct
Tritanopia#006066 · #803A3A41.9Stays distinct
Achromatopsia#525252 · #5050500.7Easily confused

Harmony

Color harmonies for #1B5583

Its complement is #744501, a dark muted brown, on the warm side of the wheel.

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

Open the Harmony Studio
  • Base#1B5583
  • Complement#744501

Complementary

Open in Harmony Studio
  • −30°#005C6D
  • Base#1B5583
  • +30°#444B86

Analogous

Open in Harmony Studio
  • Base#1B5583
  • +120°#7C3849
  • +240°#435B18

Triadic

Open in Harmony Studio
  • Base#1B5583
  • +150°#7D3C29
  • +210°#605100

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-5019: #1b5583;
}

Tailwind config

// tailwind.config.js
module.exports = {
  theme: {
    extend: {
      colors: {
        'ral-5019': '#1b5583',
      },
    },
  },
};

Tailwind v4 theme

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

@theme {
  --color-ral-5019: oklch(0.436 0.096 246.7);
}

Design token (W3C DTCG)

{
  "color": {
    "ral-5019": {
      "$type": "color",
      "$value": {
        "colorSpace": "srgb",
        "components": [0.1059, 0.3333, 0.5137],
        "hex": "#1b5583"
      },
      "$description": "RAL 5019 Capri blue (approximate sRGB)"
    }
  }
}

SwiftUI color

import SwiftUI

enum Palette {
    static let ral5019 = Color(.sRGB, red: 0.106, green: 0.333, blue: 0.514, opacity: 1)
}

Jetpack Compose color

import androidx.compose.ui.graphics.Color

object Palette {
    val Ral5019 = Color(0xFF1B5583)
}

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.

Neighbors

The eight nearest colors on this site by ΔE2000, closest first. Under 2 is hard to tell apart side by side.

Tools

Open #1B5583 in the tools

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