What color is #21C166?

#21C166 is a medium, vivid teal-green. In RGB it is rgb(33, 193, 102), and in HSL hsl(146, 71%, 44%).

Is #21C166 accessible as text?

On white, #21C166 has a contrast ratio of 2.36:1 (fails WCAG AA for body text); on black it is 8.88:1 (passes). For text placed on #21C166, use black for the best readability.

What is the closest Tailwind color to #21C166?

The nearest Tailwind CSS token is emerald-500 (#00BC7D).

What colors go well with #21C166?

#21C166 pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #C0217B. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #21C166 below.

Is #21C166 good for buttons?

#21C166 works well for buttons and highlights, but use black text on #21C166 — white text only reaches 2.36:1, below the 4.5:1 needed for normal-size labels.

Is #21C166 the same as CSS mediumseagreen?

No — #21C166 is not the CSS named color mediumseagreen, but mediumseagreen (#3CB371) is the closest CSS named color.

#21C166 Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #21C166

Not just a swatch — here's how #21C166 works with other colors. Named schemes with #21C166 in its natural role, and a note on why the supporting colors balance it.

Botanical Studio Lead · 5 colors

Lead #21C166 Secondary #4B6C3C Accent #AD6C00 Surface #EEEAD6 Anchor #3C2F20

Emerald Green leads this botanical set among foliage greens and a terracotta accent, softened by cream and grounded in bark brown.

Coastal Morning Lead · 5 colors

Lead #21C166 Accent #A8C4BA Surface #E1D9BE Secondary #9AA0A0 Anchor #1A3648

Emerald Green 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 #21C166 Secondary #ADB4B7 Surface #F1F2F0 Support #7895A3 Anchor #2D3236

Emerald Green keeps this Nordic scheme quiet — cool greys and a soft white around it, a muted-blue support and a charcoal anchor.

Warm Autumn Interior Dominant · 5 colors

Dominant #21C166 Secondary #AD6C00 Accent #677C4D Surface #F1EDDD Anchor #392B1E

This palette keeps Emerald Green as the dominant warm neutral, balanced by muted terracotta and olive earth tones and grounded by a deep espresso anchor.

Minimal Editorial Surface · 5 colors

Surface #F7F4EF Accent #21C166 Secondary #B1DBBB Support #989286 Ink #17140F

Emerald Green 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 Emerald Green carrying the quiet middle.

Build a working theme in the generator →

Color Lab

How #21C166 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 40/100

Neutral

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

Softness 47/100

Moderate

Middle-weight — neither delicate nor heavy.

Depth 30/100

Low

Airy and open — recedes, leaves the composition light.

Naturalness 51/100

Moderate

Loosely natural — an earthy edge without being rustic.

Vintage feel 29/100

Low

A faint retro warmth without tipping into sepia.

Luxury 34/100

Low

Understated — leans refined without going austere.

Brand distinctiveness 70/100

High

Bold and ownable — memorable as a primary brand color.

UI accent fit 52/100

Moderate

Workable accent with care around contrast.

Surface fit 28/100

Low

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

Print safety 61/100

High

Prints close, with a slight loss of vibrancy.

Pairs with #21C166

For UI

For branding

For interior

For fashion

People also use #21C166 with

Malachite Tiffany Blue Medium Violet Red Platinum Hunter Green

UI roles & guardrails

Primary action Safe as a filled button with near-black label. AAA

Body text Do not use for body copy on light surfaces. Avoid

Large display Only on dark surfaces. Avoid

Background Pair with #141310 text at 7.9:1. Use

Subtle surface Use #D4F1E0 for cards and hover fills. Tint 80

Avoid beside #21C09B — 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 #21C166 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: #21C166;
  --color-base-rgb: 33 193 102;
  --color-base-oklch: oklch(71.3% 0.180 151.8);
  --color-50: #F1FDF7;
  --color-100: #DBFAE9;
  --color-200: #B9F3D2;
  --color-300: #8AE5B1;
  --color-400: #5ED491;
  --color-500: #3CB972;
  --color-600: #358D5B;
  --color-700: #2B6444;
  --color-800: #1F422E;
  --color-900: #15281D;
  --color-on-base: #141310;
}

// tailwind.config.js
colors: {
  emerald-green: {
    50: '#F1FDF7',
    100: '#DBFAE9',
    200: '#B9F3D2',
    300: '#8AE5B1',
    400: '#5ED491',
    500: '#3CB972',
    600: '#358D5B',
    700: '#2B6444',
    800: '#1F422E',
    900: '#15281D',
  },
}

$base: #21C166;
$base-ink: #141310;
$base-50: #F1FDF7;
$base-100: #DBFAE9;
$base-200: #B9F3D2;
$base-300: #8AE5B1;
$base-400: #5ED491;
$base-500: #3CB972;
$base-600: #358D5B;
$base-700: #2B6444;
$base-800: #1F422E;
$base-900: #15281D;
$base-hover: #1A9951;
$base-subtle: #BDEBD1;

{
    "color": {
        "base": {
            "value": "#21C166",
            "type": "color"
        },
        "onBase": {
            "value": "#141310",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F1FDF7",
                "type": "color"
            },
            "100": {
                "value": "#DBFAE9",
                "type": "color"
            },
            "200": {
                "value": "#B9F3D2",
                "type": "color"
            },
            "300": {
                "value": "#8AE5B1",
                "type": "color"
            },
            "400": {
                "value": "#5ED491",
                "type": "color"
            },
            "500": {
                "value": "#3CB972",
                "type": "color"
            },
            "600": {
                "value": "#358D5B",
                "type": "color"
            },
            "700": {
                "value": "#2B6444",
                "type": "color"
            },
            "800": {
                "value": "#1F422E",
                "type": "color"
            },
            "900": {
                "value": "#15281D",
                "type": "color"
            }
        }
    }
}

Palettes built on #21C166

Color Lab

Pairs with #21C166

UI roles & guardrails

In real applications

Scales

Every model

Export