What color is #23403B?

#23403B is a dark low-chroma cool gray with a subtle cool cast. In RGB it is rgb(35, 64, 59), and in HSL hsl(170, 29%, 19%).

Is #23403B accessible as text?

On white, #23403B has a contrast ratio of 11.24:1 (passes WCAG AA for body text); on black it is 1.87:1 (fails). For text placed on #23403B, use white for the best readability.

What is the closest Tailwind color to #23403B?

The nearest Tailwind CSS token is neutral-700 (#404040).

What colors go well with #23403B?

As a neutral, #23403B pairs cleanly with white, off-white and light grays for text, and sits under accent hues like blue, violet, emerald or warm orange — use it as a dark surface or high-contrast base and let the accent carry the color.

Is #23403B the same as CSS darkslategray?

No — #23403B is not the CSS named color darkslategray, but darkslategray (#2F4F4F) is the closest CSS named color by perceptual color distance — it sits in a different color family, so treat it as a rough reference, not a match.

#23403B Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #23403B

Not just a swatch — here's how #23403B works with other colors. Named schemes with #23403B in its natural role, and a note on why the supporting colors balance it.

Coastal Morning Lead · 5 colors

Lead #23403B Accent #A7C4BC Surface #E0DABE Secondary #9AA0A0 Anchor #1C3549

Onyx opens this coastal palette with sea-glass and warm sand alongside it, grounded by driftwood grey and a deep-navy anchor.

Nordic Calm Accent · 5 colors

Accent #23403B Secondary #AEB4B7 Surface #F1F2F0 Support #7994A4 Anchor #2E3236

Onyx keeps this Nordic scheme quiet — cool greys and a soft white around it, a muted-blue support and a charcoal anchor.

Vintage Leather Lead · 5 colors

Lead #23403B Secondary #734F18 Surface #E4DCC0 Accent #3A5142 Anchor #5B241E

Onyx plays the worn-leather lead, deepened by saddle brown and an oxblood anchor, softened by aged cream and cooled by a muted forest green.

Luxury Packaging Feature · 5 colors

Feature #23403B Anchor #141210 Accent #BAA94D Secondary #1E2C2A Surface #F1EDE3

Onyx carries the depth in this luxury scheme, offset by a brass accent and near-black and held together by a deep neutral and an off-white surface.

Minimal Editorial Surface · 5 colors

Surface #F7F4EF Accent #23403B Secondary #586260 Support #979286 Ink #16140F

Onyx is the single accent in this high-contrast editorial system — set on near-white paper against near-black ink, with a warm grey and a desaturated tint of Onyx carrying the quiet middle.

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Color Lab

How #23403B actually behaves in design work — read from its OKLCH lightness, chroma and hue, not just its raw numbers. Ten signals to help you decide where this color earns its place.

Warmth 43/100

Neutral

Balanced temperature — flexible, sits between warm and cool schemes.

Softness 36/100

Low

Middle-weight — neither delicate nor heavy.

Depth 62/100

High

Mid depth — usable as an accent or a muted ground.

Naturalness 16/100

Very low

Reads engineered rather than organic — synthetic, digital.

Vintage feel 33/100

Low

A faint retro warmth without tipping into sepia.

Luxury 65/100

High

Restrained and premium — deep, quiet, high-end packaging and fashion.

Brand distinctiveness 14/100

Very low

Quiet and neutral — a supporting tone, not a signature.

UI accent fit 36/100

Low

Workable accent with care around contrast.

Surface fit 51/100

Moderate

Usable as a tinted surface in measured doses.

Print safety 92/100

Very high

Reproduces faithfully in CMYK — safe for packaging and print.

Pairs with #23403B

For UI

For branding

For interior

For fashion

People also use #23403B with

Hunter Green Gunmetal Gray Bistre Platinum Dark Slate Gray

UI roles & guardrails

Primary action Safe as a filled button with white label. AAA

Body text Passes on white at 16px and above. Pass

Large display Fine for headings 24px+ on white. Pass

Background Pair with white text at 11.2:1. Use

Subtle surface Use #CDDEDB for cards and hover fills. Tint 80

Avoid beside #223A3F — the hue gap is too small to read as intentional. Clash

In real applications

Not a swatch to memorise — a color to build with. Here is #23403B at work across the surfaces designers actually ship.

Website / UI

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Dashboard

Revenue

$48.2k ▲ 12%

Brand

AVELINE

Studio

Poster

Nov 14 · 8PM

NIGHT
MARKET

Packaging

BLOOM

Botanical Wash

250 ml

Interior

Every model

Export

:root {
  --color-base: #23403B;
  --color-base-rgb: 35 64 59;
  --color-base-oklch: oklch(34.7% 0.036 181.9);
  --color-50: #F5FAF9;
  --color-100: #E4F1EF;
  --color-200: #CAE2DE;
  --color-300: #A5CAC4;
  --color-400: #81B1A9;
  --color-500: #61948B;
  --color-600: #4F736D;
  --color-700: #3C534F;
  --color-800: #293735;
  --color-900: #1B2321;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  onyx: {
    50: '#F5FAF9',
    100: '#E4F1EF',
    200: '#CAE2DE',
    300: '#A5CAC4',
    400: '#81B1A9',
    500: '#61948B',
    600: '#4F736D',
    700: '#3C534F',
    800: '#293735',
    900: '#1B2321',
  },
}

$base: #23403B;
$base-ink: #FFFFFF;
$base-50: #F5FAF9;
$base-100: #E4F1EF;
$base-200: #CAE2DE;
$base-300: #A5CAC4;
$base-400: #81B1A9;
$base-500: #61948B;
$base-600: #4F736D;
$base-700: #3C534F;
$base-800: #293735;
$base-900: #1B2321;
$base-hover: #1C322E;
$base-subtle: #B3CFCA;

{
    "color": {
        "base": {
            "value": "#23403B",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F5FAF9",
                "type": "color"
            },
            "100": {
                "value": "#E4F1EF",
                "type": "color"
            },
            "200": {
                "value": "#CAE2DE",
                "type": "color"
            },
            "300": {
                "value": "#A5CAC4",
                "type": "color"
            },
            "400": {
                "value": "#81B1A9",
                "type": "color"
            },
            "500": {
                "value": "#61948B",
                "type": "color"
            },
            "600": {
                "value": "#4F736D",
                "type": "color"
            },
            "700": {
                "value": "#3C534F",
                "type": "color"
            },
            "800": {
                "value": "#293735",
                "type": "color"
            },
            "900": {
                "value": "#1B2321",
                "type": "color"
            }
        }
    }
}