What color is #040BCB?

#040BCB is a medium, vivid blue. In RGB it is rgb(4, 11, 203), and in HSL hsl(238, 96%, 41%).

Is #040BCB accessible as text?

On white, #040BCB has a contrast ratio of 10.96:1 (passes WCAG AA for body text); on black it is 1.92:1 (fails). For text placed on #040BCB, use white for the best readability.

What is the closest Tailwind color to #040BCB?

The nearest Tailwind CSS token is blue-800 (#193CB8).

What colors go well with #040BCB?

#040BCB pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #CDC604. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #040BCB below.

Is #040BCB good for buttons?

#040BCB works well for buttons and highlights, but use white text on #040BCB — black text only reaches 1.92:1, below the 4.5:1 needed for normal-size labels.

Is #040BCB the same as CSS mediumblue?

No — #040BCB is not the CSS named color mediumblue, but mediumblue (#0000CD) is the closest CSS named color.

#040BCB Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #040BCB

Not just a swatch — here's how #040BCB works with other colors. Named schemes with #040BCB in its natural role, and a note on why the supporting colors balance it.

Tech Product Signal · 5 colors

Signal #040BCB Surface #14161A Highlight #F4F6F8 Secondary #5A6672 Accent #1D50E7

Medium 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 Medium Blue.

Coastal Morning Lead · 5 colors

Lead #040BCB Accent #A5C4C2 Surface #DDDBBF Secondary #9AA0A1 Anchor #21344A

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

Berry & Cream Lead · 5 colors

Lead #040BCB Surface #F6E5D8 Anchor #5B2144 Accent #E5C2CA Secondary #322B2F

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

Minimal Editorial Surface · 5 colors

Surface #F8F4EF Accent #040BCB Secondary #50699F Support #9D8F88 Ink #18140F

Medium 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 Medium Blue carrying the quiet middle.

Sunset Warmth Glow · 5 colors

Glow #040BCB Secondary #E76A75 Accent #F79251 Anchor #573B58 Surface #F7E7D7

Medium Blue glows at the center of this sunset palette, joined by coral and gold, deepened by a plum anchor and cooled with cream.

Build a working theme in the generator →

Color Lab

How #040BCB 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 9/100

Cool

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

Softness 20/100

Low

Firm and assertive — carries weight and contrast.

Depth 69/100

High

Deep and grounding — anchors a layout, strong dark-mode base.

Naturalness 0/100

Very low

Reads engineered rather than organic — synthetic, digital.

Vintage feel 4/100

Very low

Clean and current — no dusty, aged cast.

Luxury 55/100

Moderate

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

Brand distinctiveness 100/100

Very high

Bold and ownable — memorable as a primary brand color.

UI accent fit 39/100

Low

Workable accent with care around contrast.

Surface fit 15/100

Very low

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

Print safety 52/100

Moderate

Prints close, with a slight loss of vibrancy.

Pairs with #040BCB

For UI

For branding

For interior

For fashion

People also use #040BCB with

Dodger Blue Grape Citron Gainsboro Prussian Blue

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 11.0:1. Use

Subtle surface Use #CCCDF6 for cards and hover fills. Tint 80

Avoid beside #4004CD — 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 #040BCB 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: #040BCB;
  --color-base-rgb: 4 11 203;
  --color-base-oklch: oklch(38.6% 0.260 264.6);
  --color-50: #F0F1FE;
  --color-100: #D8D9FD;
  --color-200: #B1B3FC;
  --color-300: #7A7EF6;
  --color-400: #4A4FE8;
  --color-500: #262CCF;
  --color-600: #25299D;
  --color-700: #21236E;
  --color-800: #191B48;
  --color-900: #12122C;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  medium-blue: {
    50: '#F0F1FE',
    100: '#D8D9FD',
    200: '#B1B3FC',
    300: '#7A7EF6',
    400: '#4A4FE8',
    500: '#262CCF',
    600: '#25299D',
    700: '#21236E',
    800: '#191B48',
    900: '#12122C',
  },
}

$base: #040BCB;
$base-ink: #FFFFFF;
$base-50: #F0F1FE;
$base-100: #D8D9FD;
$base-200: #B1B3FC;
$base-300: #7A7EF6;
$base-400: #4A4FE8;
$base-500: #262CCF;
$base-600: #25299D;
$base-700: #21236E;
$base-800: #191B48;
$base-900: #12122C;
$base-hover: #0309A4;
$base-subtle: #B1B3F3;

{
    "color": {
        "base": {
            "value": "#040BCB",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F0F1FE",
                "type": "color"
            },
            "100": {
                "value": "#D8D9FD",
                "type": "color"
            },
            "200": {
                "value": "#B1B3FC",
                "type": "color"
            },
            "300": {
                "value": "#7A7EF6",
                "type": "color"
            },
            "400": {
                "value": "#4A4FE8",
                "type": "color"
            },
            "500": {
                "value": "#262CCF",
                "type": "color"
            },
            "600": {
                "value": "#25299D",
                "type": "color"
            },
            "700": {
                "value": "#21236E",
                "type": "color"
            },
            "800": {
                "value": "#191B48",
                "type": "color"
            },
            "900": {
                "value": "#12122C",
                "type": "color"
            }
        }
    }
}

Palettes built on #040BCB

Color Lab

Pairs with #040BCB

UI roles & guardrails

In real applications

Scales

Every model

Export