What color is #0300BB?

#0300BB is a dark, vivid blue. In RGB it is rgb(3, 0, 187), and in HSL hsl(241, 100%, 37%).

Is #0300BB accessible as text?

On white, #0300BB has a contrast ratio of 12.20:1 (passes WCAG AA for body text); on black it is 1.72:1 (fails). For text placed on #0300BB, use white for the best readability.

What is the closest Tailwind color to #0300BB?

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

What colors go well with #0300BB?

#0300BB pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #BABD00. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #0300BB below.

Is #0300BB good for buttons?

#0300BB works well for buttons and highlights, but use white text on #0300BB — black text only reaches 1.72:1, below the 4.5:1 needed for normal-size labels.

Is #0300BB the same as CSS mediumblue?

No — #0300BB is not the CSS named color mediumblue, but mediumblue (#0000CD) is the closest CSS named color.

#0300BB Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #0300BB

Not just a swatch — here's how #0300BB works with other colors. Named schemes with #0300BB in its natural role, and a note on why the supporting colors balance it.

Luxury Packaging Feature · 5 colors

Feature #0300BB Anchor #141210 Accent #ACAE53 Secondary #242933 Surface #F0EEE3

Medium Blue 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.

Tech Product Signal · 5 colors

Signal #0300BB Surface #14161A Highlight #F4F6F8 Secondary #5A6672 Accent #1949D8

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.

Moody Editorial Color · 5 colors

Color #0300BB Anchor #2A2A2E Secondary #6E6E74 Surface #E9E7DA Accent #20006C

Medium Blue adds the colour to this moody editorial scheme — charcoal and a mid-grey around it, a bone highlight, and a muted jewel accent drawn from Medium Blue.

Coastal Morning Lead · 5 colors

Lead #0300BB 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.

Minimal Editorial Surface · 5 colors

Surface #F8F4EF Accent #0300BB Secondary #4A6294 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.

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Color Lab

How #0300BB 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

Very low

Firm and assertive — carries weight and contrast.

Depth 71/100

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 6/100

Very low

Clean and current — no dusty, aged cast.

Luxury 58/100

Moderate

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

Brand distinctiveness 96/100

Very high

Bold and ownable — memorable as a primary brand color.

UI accent fit 38/100

Low

Workable accent with care around contrast.

Surface fit 17/100

Very low

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

Print safety 55/100

Moderate

Prints close, with a slight loss of vibrancy.

Pairs with #0300BB

For UI

For branding

For interior

For fashion

People also use #0300BB with

Azure 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 12.2:1. Use

Subtle surface Use #C9C8F6 for cards and hover fills. Tint 80

Avoid beside #4200BD — 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 #0300BB 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: #0300BB;
  --color-base-rgb: 3 0 187;
  --color-base-oklch: oklch(35.9% 0.248 264.4);
  --color-50: #F1F0FE;
  --color-100: #D8D8FD;
  --color-200: #B2B1FC;
  --color-300: #7977F8;
  --color-400: #4946EC;
  --color-500: #2522D2;
  --color-600: #25239F;
  --color-700: #201F70;
  --color-800: #191848;
  --color-900: #12112C;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  medium-blue: {
    50: '#F1F0FE',
    100: '#D8D8FD',
    200: '#B2B1FC',
    300: '#7977F8',
    400: '#4946EC',
    500: '#2522D2',
    600: '#25239F',
    700: '#201F70',
    800: '#191848',
    900: '#12112C',
  },
}

$base: #0300BB;
$base-ink: #FFFFFF;
$base-50: #F1F0FE;
$base-100: #D8D8FD;
$base-200: #B2B1FC;
$base-300: #7977F8;
$base-400: #4946EC;
$base-500: #2522D2;
$base-600: #25239F;
$base-700: #201F70;
$base-800: #191848;
$base-900: #12112C;
$base-hover: #030097;
$base-subtle: #ABAAF3;

{
    "color": {
        "base": {
            "value": "#0300BB",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F1F0FE",
                "type": "color"
            },
            "100": {
                "value": "#D8D8FD",
                "type": "color"
            },
            "200": {
                "value": "#B2B1FC",
                "type": "color"
            },
            "300": {
                "value": "#7977F8",
                "type": "color"
            },
            "400": {
                "value": "#4946EC",
                "type": "color"
            },
            "500": {
                "value": "#2522D2",
                "type": "color"
            },
            "600": {
                "value": "#25239F",
                "type": "color"
            },
            "700": {
                "value": "#201F70",
                "type": "color"
            },
            "800": {
                "value": "#191848",
                "type": "color"
            },
            "900": {
                "value": "#12112C",
                "type": "color"
            }
        }
    }
}

Palettes built on #0300BB

Color Lab

Pairs with #0300BB

UI roles & guardrails

In real applications

Scales

Every model

Export