What color is #100B21?

#100B21 is a very dark indigo. In RGB it is rgb(16, 11, 33), and in HSL hsl(254, 50%, 9%).

Is #100B21 accessible as text?

On white, #100B21 has a contrast ratio of 19.23:1 (passes WCAG AA for body text); on black it is 1.09:1 (fails). For text placed on #100B21, use white for the best readability.

What is the closest Tailwind color to #100B21?

The nearest Tailwind CSS token is mauve-950 (#0C090C).

What colors go well with #100B21?

#100B21 pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #1D220B. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #100B21 below.

Is #100B21 good for buttons?

#100B21 works well for buttons and highlights, but use white text on #100B21 — black text only reaches 1.09:1, below the 4.5:1 needed for normal-size labels.

Is #100B21 the same as CSS midnightblue?

No — #100B21 is not the CSS named color midnightblue, but midnightblue (#191970) 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.

#100B21 Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #100B21

Not just a swatch — here's how #100B21 works with other colors. Named schemes with #100B21 in its natural role, and a note on why the supporting colors balance it.

Coastal Morning Lead · 5 colors

Lead #100B21 Accent #A5C4C3 Surface #E9D6BF Secondary #9AA0A1 Anchor #22334A

Jet Black 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 #100B21 Secondary #AFB4B8 Surface #F1F2F0 Support #7F92A7 Anchor #2E3236

Jet Black 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 #100B21 Secondary #7E4632 Surface #EDD8C2 Accent #355248 Anchor #582237

Jet Black 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 #100B21 Anchor #141210 Accent #DA9857 Secondary #292732 Surface #F3ECE3

Jet Black 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 #F8F4EF Accent #100B21 Secondary #302F38 Support #9D9088 Ink #18140F

Jet Black 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 Jet Black carrying the quiet middle.

Build a working theme in the generator →

Color Lab

How #100B21 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 44/100

Neutral

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

Softness 18/100

Very low

Firm and assertive — carries weight and contrast.

Depth 79/100

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 23/100

Low

Clean and current — no dusty, aged cast.

Luxury 79/100

High

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

Brand distinctiveness 17/100

Very low

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

UI accent fit 7/100

Very low

Weak as an action color — too pale, too dark or too muted to signal.

Surface fit 60/100

High

Calm enough for large fills — backgrounds, cards, sections.

Print safety 94/100

Very high

Reproduces faithfully in CMYK — safe for packaging and print.

Pairs with #100B21

For UI

For branding

For interior

For fashion

People also use #100B21 with

Navy Graphite Gainsboro Russian Violet

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 19.2:1. Use

Subtle surface Use #C8C0E1 for cards and hover fills. Tint 80

Avoid beside #180B22 — 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 #100B21 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: #100B21;
  --color-base-rgb: 16 11 33;
  --color-base-oklch: oklch(17.0% 0.045 291.4);
  --color-50: #F5F3FC;
  --color-100: #E5E0F5;
  --color-200: #CBC2EB;
  --color-300: #A697D8;
  --color-400: #8370C2;
  --color-500: #634EA6;
  --color-600: #504280;
  --color-700: #3D335C;
  --color-800: #2A243C;
  --color-900: #1B1825;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  jet-black: {
    50: '#F5F3FC',
    100: '#E5E0F5',
    200: '#CBC2EB',
    300: '#A697D8',
    400: '#8370C2',
    500: '#634EA6',
    600: '#504280',
    700: '#3D335C',
    800: '#2A243C',
    900: '#1B1825',
  },
}

$base: #100B21;
$base-ink: #FFFFFF;
$base-50: #F5F3FC;
$base-100: #E5E0F5;
$base-200: #CBC2EB;
$base-300: #A697D8;
$base-400: #8370C2;
$base-500: #634EA6;
$base-600: #504280;
$base-700: #3D335C;
$base-800: #2A243C;
$base-900: #1B1825;
$base-hover: #0D091C;
$base-subtle: #AB9FD4;

{
    "color": {
        "base": {
            "value": "#100B21",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F5F3FC",
                "type": "color"
            },
            "100": {
                "value": "#E5E0F5",
                "type": "color"
            },
            "200": {
                "value": "#CBC2EB",
                "type": "color"
            },
            "300": {
                "value": "#A697D8",
                "type": "color"
            },
            "400": {
                "value": "#8370C2",
                "type": "color"
            },
            "500": {
                "value": "#634EA6",
                "type": "color"
            },
            "600": {
                "value": "#504280",
                "type": "color"
            },
            "700": {
                "value": "#3D335C",
                "type": "color"
            },
            "800": {
                "value": "#2A243C",
                "type": "color"
            },
            "900": {
                "value": "#1B1825",
                "type": "color"
            }
        }
    }
}

Palettes built on #100B21

Color Lab

Pairs with #100B21

UI roles & guardrails

In real applications

Scales

Every model

Export