What color is #2121AB?

#2121AB is a medium blue. In RGB it is rgb(33, 33, 171), and in HSL hsl(240, 68%, 40%).

Is #2121AB accessible as text?

On white, #2121AB has a contrast ratio of 11.23:1 (passes WCAG AA for body text); on black it is 1.87:1 (fails). For text placed on #2121AB, use white for the best readability.

What is the closest Tailwind color to #2121AB?

The nearest Tailwind CSS token is indigo-800 (#372AAC).

What colors go well with #2121AB?

#2121AB pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #ABAB21. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #2121AB below.

Is #2121AB good for buttons?

#2121AB works well for buttons and highlights, but use white text on #2121AB — black text only reaches 1.87:1, below the 4.5:1 needed for normal-size labels.

Is #2121AB the same as CSS mediumblue?

No — #2121AB is not the CSS named color mediumblue, but mediumblue (#0000CD) is the closest CSS named color.

#2121AB Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #2121AB

Not just a swatch — here's how #2121AB works with other colors. Named schemes with #2121AB in its natural role, and a note on why the supporting colors balance it.

Luxury Packaging Feature · 5 colors

Feature #2121AB Anchor #141210 Accent #DC9659 Secondary #252933 Surface #F3ECE3

Klein 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 #2121AB Surface #14161A Highlight #F4F6F8 Secondary #5B6672 Accent #3C51C9

Klein 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 Klein Blue.

Moody Editorial Color · 5 colors

Color #2121AB Anchor #2A2A2E Secondary #6E6E74 Surface #EEE5DB Accent #260061

Klein 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 Klein Blue.

Coastal Morning Lead · 5 colors

Lead #2121AB Accent #A5C4C2 Surface #EAD5C0 Secondary #9AA0A1 Anchor #21344A

Klein 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 #2121AB Secondary #576591 Support #9D8F88 Ink #18140F

Klein 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 Klein Blue carrying the quiet middle.

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Color Lab

How #2121AB 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 24/100

Low

Firm and assertive — carries weight and contrast.

Depth 68/100

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 17/100

Very low

Clean and current — no dusty, aged cast.

Luxury 61/100

High

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

Brand distinctiveness 80/100

Very high

Bold and ownable — memorable as a primary brand color.

UI accent fit 54/100

Moderate

Workable accent with care around contrast.

Surface fit 16/100

Very low

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

Print safety 65/100

High

Prints close, with a slight loss of vibrancy.

Pairs with #2121AB

For UI

For branding

For interior

For fashion

People also use #2121AB with

Steel 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 11.2:1. Use

Subtle surface Use #D1D1EF for cards and hover fills. Tint 80

Avoid beside #4F21AB — 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 #2121AB 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: #2121AB;
  --color-base-rgb: 33 33 171;
  --color-base-oklch: oklch(37.2% 0.207 270.4);
  --color-50: #F2F2FD;
  --color-100: #DCDCF9;
  --color-200: #BBBBF2;
  --color-300: #8C8CE3;
  --color-400: #6161D1;
  --color-500: #3F3FB6;
  --color-600: #37378B;
  --color-700: #2C2C63;
  --color-800: #202041;
  --color-900: #151528;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  klein-blue: {
    50: '#F2F2FD',
    100: '#DCDCF9',
    200: '#BBBBF2',
    300: '#8C8CE3',
    400: '#6161D1',
    500: '#3F3FB6',
    600: '#37378B',
    700: '#2C2C63',
    800: '#202041',
    900: '#151528',
  },
}

$base: #2121AB;
$base-ink: #FFFFFF;
$base-50: #F2F2FD;
$base-100: #DCDCF9;
$base-200: #BBBBF2;
$base-300: #8C8CE3;
$base-400: #6161D1;
$base-500: #3F3FB6;
$base-600: #37378B;
$base-700: #2C2C63;
$base-800: #202041;
$base-900: #151528;
$base-hover: #1A1A89;
$base-subtle: #B9B9E9;

{
    "color": {
        "base": {
            "value": "#2121AB",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F2F2FD",
                "type": "color"
            },
            "100": {
                "value": "#DCDCF9",
                "type": "color"
            },
            "200": {
                "value": "#BBBBF2",
                "type": "color"
            },
            "300": {
                "value": "#8C8CE3",
                "type": "color"
            },
            "400": {
                "value": "#6161D1",
                "type": "color"
            },
            "500": {
                "value": "#3F3FB6",
                "type": "color"
            },
            "600": {
                "value": "#37378B",
                "type": "color"
            },
            "700": {
                "value": "#2C2C63",
                "type": "color"
            },
            "800": {
                "value": "#202041",
                "type": "color"
            },
            "900": {
                "value": "#151528",
                "type": "color"
            }
        }
    }
}

Palettes built on #2121AB

Color Lab

Pairs with #2121AB

UI roles & guardrails

In real applications

Scales

Every model

Export