What color is #166CCF?

#166CCF is a medium, vivid blue. In RGB it is rgb(22, 108, 207), and in HSL hsl(212, 81%, 45%).

Is #166CCF accessible as text?

On white, #166CCF has a contrast ratio of 5.15:1 (passes WCAG AA for body text); on black it is 4.08:1 (fails). For text placed on #166CCF, use white for the best readability.

What is the closest Tailwind color to #166CCF?

The nearest Tailwind CSS token is sky-700 (#0069A8).

What colors go well with #166CCF?

#166CCF pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #D07916. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #166CCF below.

Is #166CCF good for buttons?

#166CCF works well for buttons and highlights, but use white text on #166CCF — black text only reaches 4.08:1, below the 4.5:1 needed for normal-size labels.

Is #166CCF the same as CSS royalblue?

No — #166CCF is not the CSS named color royalblue, but royalblue (#4169E1) is the closest CSS named color.

#166CCF Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #166CCF

Not just a swatch — here's how #166CCF works with other colors. Named schemes with #166CCF in its natural role, and a note on why the supporting colors balance it.

Coastal Morning Lead · 5 colors

Lead #166CCF Accent #A5C4C1 Surface #DDDBBF Secondary #9AA0A1 Anchor #20344A

True Blue opens this coastal palette with sea-glass and warm sand alongside it, grounded by driftwood grey and a deep-navy anchor.

Tech Product Signal · 5 colors

Signal #166CCF Surface #14161A Highlight #F4F6F8 Secondary #5A6672 Accent #4C93EE

True 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 True Blue.

Vintage Leather Lead · 5 colors

Lead #166CCF Secondary #7F4537 Surface #E1DDC1 Accent #375246 Anchor #57233B

True Blue plays the worn-leather lead, deepened by saddle brown and an oxblood anchor, softened by aged cream and cooled by a muted forest green.

Berry & Cream Lead · 5 colors

Lead #166CCF Surface #EDE9D6 Anchor #5A2145 Accent #E4C2CA Secondary #322B2F

True Blue sits between cream and a deep berry here, softened by a blush accent and grounded by charcoal.

Minimal Editorial Surface · 5 colors

Surface #F6F4EF Accent #166CCF Secondary #809ABD Support #9D8F89 Ink #16140F

True 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 True Blue carrying the quiet middle.

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Color Lab

How #166CCF 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 5/100

Cool

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

Softness 37/100

Low

Middle-weight — neither delicate nor heavy.

Depth 48/100

Moderate

Mid depth — usable as an accent or a muted ground.

Naturalness 0/100

Very low

Reads engineered rather than organic — synthetic, digital.

Vintage feel 34/100

Low

A faint retro warmth without tipping into sepia.

Luxury 50/100

Moderate

Understated — leans refined without going austere.

Brand distinctiveness 46/100

Moderate

Recognisable but shares space with nearby hues.

UI accent fit 96/100

Very high

Strong interactive accent — visible and can carry a legible label.

Surface fit 11/100

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 #166CCF

For UI

For branding

For interior

For fashion

People also use #166CCF with

Turquoise Medium Blue Ochre Gainsboro Charcoal

UI roles & guardrails

Primary action Safe as a filled button with white label. AA

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 5.1:1. Use

Subtle surface Use #D3E2F3 for cards and hover fills. Tint 80

Avoid beside #162FD0 — 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 #166CCF at work across the surfaces designers actually ship.

Website / UI

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Dashboard

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$48.2k ▲ 12%

Brand

AVELINE

Studio

Poster

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NIGHT
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Packaging

BLOOM

Botanical Wash

250 ml

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Export

:root {
  --color-base: #166CCF;
  --color-base-rgb: 22 108 207;
  --color-base-oklch: oklch(54.0% 0.171 256.0);
  --color-50: #F1F7FE;
  --color-100: #D9E9FC;
  --color-200: #B5D4F7;
  --color-300: #83B4EC;
  --color-400: #5695DC;
  --color-500: #3376C2;
  --color-600: #2E5E93;
  --color-700: #274568;
  --color-800: #1D2F44;
  --color-900: #141E2A;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  true-blue: {
    50: '#F1F7FE',
    100: '#D9E9FC',
    200: '#B5D4F7',
    300: '#83B4EC',
    400: '#5695DC',
    500: '#3376C2',
    600: '#2E5E93',
    700: '#274568',
    800: '#1D2F44',
    900: '#141E2A',
  },
}

$base: #166CCF;
$base-ink: #FFFFFF;
$base-50: #F1F7FE;
$base-100: #D9E9FC;
$base-200: #B5D4F7;
$base-300: #83B4EC;
$base-400: #5695DC;
$base-500: #3376C2;
$base-600: #2E5E93;
$base-700: #274568;
$base-800: #1D2F44;
$base-900: #141E2A;
$base-hover: #1157A6;
$base-subtle: #BBD3EF;

{
    "color": {
        "base": {
            "value": "#166CCF",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F1F7FE",
                "type": "color"
            },
            "100": {
                "value": "#D9E9FC",
                "type": "color"
            },
            "200": {
                "value": "#B5D4F7",
                "type": "color"
            },
            "300": {
                "value": "#83B4EC",
                "type": "color"
            },
            "400": {
                "value": "#5695DC",
                "type": "color"
            },
            "500": {
                "value": "#3376C2",
                "type": "color"
            },
            "600": {
                "value": "#2E5E93",
                "type": "color"
            },
            "700": {
                "value": "#274568",
                "type": "color"
            },
            "800": {
                "value": "#1D2F44",
                "type": "color"
            },
            "900": {
                "value": "#141E2A",
                "type": "color"
            }
        }
    }
}

Palettes built on #166CCF

Color Lab

Pairs with #166CCF

UI roles & guardrails

In real applications

Scales

Every model

Export