What color is #034F9B?

#034F9B is a dark, vivid blue. In RGB it is rgb(3, 79, 155), and in HSL hsl(210, 96%, 31%).

Is #034F9B accessible as text?

On white, #034F9B has a contrast ratio of 8.09:1 (passes WCAG AA for body text); on black it is 2.60:1 (fails). For text placed on #034F9B, use white for the best readability.

What is the closest Tailwind color to #034F9B?

The nearest Tailwind CSS token is sky-800 (#00598A).

What colors go well with #034F9B?

#034F9B pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #9B4F03. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #034F9B below.

Is #034F9B good for buttons?

#034F9B works well for buttons and highlights, but use white text on #034F9B — black text only reaches 2.60:1, below the 4.5:1 needed for normal-size labels.

Is #034F9B the same as CSS darkslateblue?

No — #034F9B is not the CSS named color darkslateblue, but darkslateblue (#483D8B) is the closest CSS named color.

#034F9B Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #034F9B

Not just a swatch — here's how #034F9B works with other colors. Named schemes with #034F9B in its natural role, and a note on why the supporting colors balance it.

Coastal Morning Lead · 5 colors

Lead #034F9B Accent #A5C4C1 Surface #DDDBBF Secondary #9AA0A1 Anchor #20344A

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

Tech Product Signal · 5 colors

Signal #034F9B Surface #14161A Highlight #F4F6F8 Secondary #5A6672 Accent #3A74BA

Cobalt Blue is the vivid signal in this product UI — on a near-black surface with cool white, a slate grey and a lighter tint of Cobalt Blue.

Vintage Leather Lead · 5 colors

Lead #034F9B Secondary #7F4537 Surface #E1DDC1 Accent #375246 Anchor #57233B

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

Berry & Cream Lead · 5 colors

Lead #034F9B Surface #EDE9D6 Anchor #5A2145 Accent #E4C2CA Secondary #322B2F

Cobalt Blue sits between cream and a deep berry here, softened by a blush accent and grounded by charcoal.

Minimal Editorial Surface · 5 colors

Surface #F6F4EF Accent #034F9B Secondary #657A95 Support #9D8F89 Ink #16140F

Cobalt Blue 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 Cobalt Blue carrying the quiet middle.

Build a working theme in the generator →

Color Lab

How #034F9B 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 12/100

Cool

Reads cool and recessive — calming, technical, good for trust-led UI.

Softness 34/100

Low

Middle-weight — neither delicate nor heavy.

Depth 58/100

Moderate

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

Naturalness 0/100

Very low

Reads engineered rather than organic — synthetic, digital.

Vintage feel 37/100

Low

A faint retro warmth without tipping into sepia.

Luxury 61/100

High

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

Brand distinctiveness 38/100

Low

Recognisable but shares space with nearby hues.

UI accent fit 85/100

Very high

Strong interactive accent — visible and can carry a legible label.

Surface fit 14/100

Very low

Too saturated or mid-toned for big areas — keep it to accents.

Print safety 71/100

High

Reproduces faithfully in CMYK — safe for packaging and print.

Pairs with #034F9B

For UI

For branding

For interior

For fashion

People also use #034F9B with

Tiffany Blue Zaffre Saddle Brown Gainsboro Charcoal

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 8.1:1. Use

Subtle surface Use #C3DCF4 for cards and hover fills. Tint 80

Avoid beside #031C9B — 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 #034F9B at work across the surfaces designers actually ship.

Website / UI

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Build faster.

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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: #034F9B;
  --color-base-rgb: 3 79 155;
  --color-base-oklch: oklch(43.3% 0.140 254.9);
  --color-50: #F0F7FE;
  --color-100: #D8EBFD;
  --color-200: #B1D6FC;
  --color-300: #7AB8F6;
  --color-400: #4A99E8;
  --color-500: #267ACF;
  --color-600: #25619D;
  --color-700: #21476E;
  --color-800: #193048;
  --color-900: #121F2C;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  cobalt-blue: {
    50: '#F0F7FE',
    100: '#D8EBFD',
    200: '#B1D6FC',
    300: '#7AB8F6',
    400: '#4A99E8',
    500: '#267ACF',
    600: '#25619D',
    700: '#21476E',
    800: '#193048',
    900: '#121F2C',
  },
}

$base: #034F9B;
$base-ink: #FFFFFF;
$base-50: #F0F7FE;
$base-100: #D8EBFD;
$base-200: #B1D6FC;
$base-300: #7AB8F6;
$base-400: #4A99E8;
$base-500: #267ACF;
$base-600: #25619D;
$base-700: #21476E;
$base-800: #193048;
$base-900: #121F2C;
$base-hover: #033F7C;
$base-subtle: #A4CAF1;

{
    "color": {
        "base": {
            "value": "#034F9B",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F0F7FE",
                "type": "color"
            },
            "100": {
                "value": "#D8EBFD",
                "type": "color"
            },
            "200": {
                "value": "#B1D6FC",
                "type": "color"
            },
            "300": {
                "value": "#7AB8F6",
                "type": "color"
            },
            "400": {
                "value": "#4A99E8",
                "type": "color"
            },
            "500": {
                "value": "#267ACF",
                "type": "color"
            },
            "600": {
                "value": "#25619D",
                "type": "color"
            },
            "700": {
                "value": "#21476E",
                "type": "color"
            },
            "800": {
                "value": "#193048",
                "type": "color"
            },
            "900": {
                "value": "#121F2C",
                "type": "color"
            }
        }
    }
}