What color is #21ECFF?

#21ECFF is a medium, vivid cyan. In RGB it is rgb(33, 236, 255), and in HSL hsl(185, 100%, 56%).

Is #21ECFF accessible as text?

On white, #21ECFF has a contrast ratio of 1.45:1 (fails WCAG AA for body text); on black it is 14.51:1 (passes). For text placed on #21ECFF, use black for the best readability.

What is the closest Tailwind color to #21ECFF?

The nearest Tailwind CSS token is cyan-300 (#53EAFD).

What colors go well with #21ECFF?

#21ECFF pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #FF311F. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #21ECFF below.

Is #21ECFF good for buttons?

#21ECFF works well for buttons and highlights, but use black text on #21ECFF — white text only reaches 1.45:1, below the 4.5:1 needed for normal-size labels.

Is #21ECFF the same as CSS aqua?

No — #21ECFF is not the CSS named color aqua, but aqua (#00FFFF) is the closest CSS named color.

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

Palettes built on #21ECFF

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

Coastal Morning Lead · 5 colors

Lead #21ECFF Accent #A6C4BE Surface #DFDABE Secondary #9AA0A0 Anchor #1D3549

Cyan 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 #21ECFF Secondary #AEB4B8 Surface #F1F2F0 Support #7A94A5 Anchor #2E3236

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

Tech Product Signal · 5 colors

Signal #21ECFF Surface #14161A Highlight #F4F6F8 Secondary #596671 Accent #7DFFFF

Cyan is the vivid signal in this product UI — on a near-black surface with cool white, a slate grey and a lighter tint of Cyan.

Minimal Editorial Surface · 5 colors

Surface #F6F4EF Accent #21ECFF Secondary #D4FFFF Support #979286 Ink #16140F

Cyan 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 Cyan carrying the quiet middle.

Modern Café Dominant · 5 colors

Dominant #21ECFF Anchor #372C1D Surface #EBE5D0 Accent #7F9D73 Secondary #3A3933

Cyan anchors this café scheme as the warm mid-tone, lifted by latte cream and a muted sage accent and grounded by espresso brown and a warm charcoal.

Build a working theme in the generator →

Color Lab

How #21ECFF 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 11/100

Cool

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

Softness 62/100

High

Soft and easy on the eye — gentle backdrops, calm surfaces.

Depth 14/100

Very low

Airy and open — recedes, leaves the composition light.

Naturalness 6/100

Very low

Reads engineered rather than organic — synthetic, digital.

Vintage feel 23/100

Low

Clean and current — no dusty, aged cast.

Luxury 20/100

Very low

Playful and accessible rather than exclusive.

Brand distinctiveness 55/100

Moderate

Recognisable but shares space with nearby hues.

UI accent fit 15/100

Very low

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

Surface fit 43/100

Moderate

Usable as a tinted surface in measured doses.

Print safety 62/100

High

Prints close, with a slight loss of vibrancy.

Pairs with #21ECFF

For UI

For branding

For interior

For fashion

People also use #21ECFF with

Medium Spring Green Azure Vermilion Platinum Dark Slate Gray

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 12.8:1. Use

Subtle surface Use #D8F6F9 for cards and hover fills. Tint 80

Avoid beside #1FA2FF — 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 #21ECFF 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: #21ECFF;
  --color-base-rgb: 33 236 255;
  --color-base-oklch: oklch(86.2% 0.144 205.5);
  --color-50: #F0FDFE;
  --color-100: #D8FAFD;
  --color-200: #B1F5FC;
  --color-300: #77EDF8;
  --color-400: #46DEEC;
  --color-500: #22C4D2;
  --color-600: #23959F;
  --color-700: #1F6970;
  --color-800: #184448;
  --color-900: #112A2C;
  --color-on-base: #141310;
}

// tailwind.config.js
colors: {
  cyan: {
    50: '#F0FDFE',
    100: '#D8FAFD',
    200: '#B1F5FC',
    300: '#77EDF8',
    400: '#46DEEC',
    500: '#22C4D2',
    600: '#23959F',
    700: '#1F6970',
    800: '#184448',
    900: '#112A2C',
  },
}

$base: #21ECFF;
$base-ink: #141310;
$base-50: #F0FDFE;
$base-100: #D8FAFD;
$base-200: #B1F5FC;
$base-300: #77EDF8;
$base-400: #46DEEC;
$base-500: #22C4D2;
$base-600: #23959F;
$base-700: #1F6970;
$base-800: #184448;
$base-900: #112A2C;
$base-hover: #00D1E4;
$base-subtle: #C4F3F7;

{
    "color": {
        "base": {
            "value": "#21ECFF",
            "type": "color"
        },
        "onBase": {
            "value": "#141310",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F0FDFE",
                "type": "color"
            },
            "100": {
                "value": "#D8FAFD",
                "type": "color"
            },
            "200": {
                "value": "#B1F5FC",
                "type": "color"
            },
            "300": {
                "value": "#77EDF8",
                "type": "color"
            },
            "400": {
                "value": "#46DEEC",
                "type": "color"
            },
            "500": {
                "value": "#22C4D2",
                "type": "color"
            },
            "600": {
                "value": "#23959F",
                "type": "color"
            },
            "700": {
                "value": "#1F6970",
                "type": "color"
            },
            "800": {
                "value": "#184448",
                "type": "color"
            },
            "900": {
                "value": "#112A2C",
                "type": "color"
            }
        }
    }
}

Palettes built on #21ECFF

Color Lab

Pairs with #21ECFF

UI roles & guardrails

In real applications

Scales

Every model

Export