What color is #378ACE?

#378ACE is a medium cyan-blue. In RGB it is rgb(55, 138, 206), and in HSL hsl(207, 61%, 51%).

Is #378ACE accessible as text?

On white, #378ACE has a contrast ratio of 3.69:1 (fails WCAG AA for body text); on black it is 5.69:1 (passes). For text placed on #378ACE, use black for the best readability.

What is the closest Tailwind color to #378ACE?

The nearest Tailwind CSS token is sky-600 (#0084D1).

What colors go well with #378ACE?

#378ACE pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #CE7A36. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #378ACE below.

Is #378ACE good for buttons?

#378ACE works well for buttons and highlights, but use black text on #378ACE — white text only reaches 3.69:1, below the 4.5:1 needed for normal-size labels.

Is #378ACE the same as CSS steelblue?

No — #378ACE is not the CSS named color steelblue, but steelblue (#4682B4) is the closest CSS named color.

#378ACE Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #378ACE

Not just a swatch — here's how #378ACE works with other colors. Named schemes with #378ACE in its natural role, and a note on why the supporting colors balance it.

Coastal Morning Lead · 5 colors

Lead #378ACE Accent #A5C4C0 Surface #DDDBBF Secondary #9AA0A1 Anchor #20344A

Steel 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 #378ACE Surface #14161A Highlight #F4F6F8 Secondary #5A6672 Accent #68B0EF

Steel 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 Steel Blue.

Vintage Leather Lead · 5 colors

Lead #378ACE Secondary #7F4438 Surface #E1DDC0 Accent #375245 Anchor #57233C

Steel 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 #378ACE Surface #EDE9D6 Anchor #5A2246 Accent #E4C2CB Secondary #322B2F

Steel 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 #378ACE Secondary #99B3CB Support #969386 Ink #16140F

Steel 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 Steel Blue carrying the quiet middle.

Build a working theme in the generator →

Color Lab

How #378ACE 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 13/100

Cool

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

Softness 47/100

Moderate

Middle-weight — neither delicate nor heavy.

Depth 39/100

Low

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

Naturalness 0/100

Very low

Reads engineered rather than organic — synthetic, digital.

Vintage feel 43/100

Moderate

A faint retro warmth without tipping into sepia.

Luxury 46/100

Moderate

Understated — leans refined without going austere.

Brand distinctiveness 35/100

Low

Recognisable but shares space with nearby hues.

UI accent fit 88/100

Very high

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

Surface fit 24/100

Low

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

Print safety 71/100

High

Reproduces faithfully in CMYK — safe for packaging and print.

Pairs with #378ACE

For UI

For branding

For interior

For fashion

People also use #378ACE with

Medium Turquoise Cerulean Bronze Gainsboro Charcoal

UI roles & guardrails

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

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

Large display Fine for headings 24px+ on white. Pass

Background Pair with #141310 text at 5.0:1. Use

Subtle surface Use #DBE7F1 for cards and hover fills. Tint 80

Avoid beside #3657CE — 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 #378ACE 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: #378ACE;
  --color-base-rgb: 55 138 206;
  --color-base-oklch: oklch(61.5% 0.130 246.9);
  --color-50: #F2F8FC;
  --color-100: #DDECF8;
  --color-200: #BDD9EF;
  --color-300: #90BCDF;
  --color-400: #679ECB;
  --color-500: #4580B0;
  --color-600: #3B6587;
  --color-700: #2F4A60;
  --color-800: #22323F;
  --color-900: #161F27;
  --color-on-base: #141310;
}

// tailwind.config.js
colors: {
  steel-blue: {
    50: '#F2F8FC',
    100: '#DDECF8',
    200: '#BDD9EF',
    300: '#90BCDF',
    400: '#679ECB',
    500: '#4580B0',
    600: '#3B6587',
    700: '#2F4A60',
    800: '#22323F',
    900: '#161F27',
  },
}

$base: #378ACE;
$base-ink: #141310;
$base-50: #F2F8FC;
$base-100: #DDECF8;
$base-200: #BDD9EF;
$base-300: #90BCDF;
$base-400: #679ECB;
$base-500: #4580B0;
$base-600: #3B6587;
$base-700: #2F4A60;
$base-800: #22323F;
$base-900: #161F27;
$base-hover: #296EA8;
$base-subtle: #C8DBEB;

{
    "color": {
        "base": {
            "value": "#378ACE",
            "type": "color"
        },
        "onBase": {
            "value": "#141310",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F2F8FC",
                "type": "color"
            },
            "100": {
                "value": "#DDECF8",
                "type": "color"
            },
            "200": {
                "value": "#BDD9EF",
                "type": "color"
            },
            "300": {
                "value": "#90BCDF",
                "type": "color"
            },
            "400": {
                "value": "#679ECB",
                "type": "color"
            },
            "500": {
                "value": "#4580B0",
                "type": "color"
            },
            "600": {
                "value": "#3B6587",
                "type": "color"
            },
            "700": {
                "value": "#2F4A60",
                "type": "color"
            },
            "800": {
                "value": "#22323F",
                "type": "color"
            },
            "900": {
                "value": "#161F27",
                "type": "color"
            }
        }
    }
}

Palettes built on #378ACE

Color Lab

Pairs with #378ACE

UI roles & guardrails

In real applications

Scales

Every model

Export