What color is #378CB4?

#378CB4 is a medium cyan-blue. In RGB it is rgb(55, 140, 180), and in HSL hsl(199, 53%, 46%).

Is #378CB4 accessible as text?

On white, #378CB4 has a contrast ratio of 3.77:1 (fails WCAG AA for body text); on black it is 5.57:1 (passes). For text placed on #378CB4, use black for the best readability.

What is the closest Tailwind color to #378CB4?

The nearest Tailwind CSS token is cyan-600 (#0092B8).

What colors go well with #378CB4?

#378CB4 pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #B35F37. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #378CB4 below.

Is #378CB4 good for buttons?

#378CB4 works well for buttons and highlights, but use black text on #378CB4 — white text only reaches 3.77:1, below the 4.5:1 needed for normal-size labels.

Is #378CB4 the same as CSS steelblue?

No — #378CB4 is not the CSS named color steelblue, but steelblue (#4682B4) is the closest CSS named color.

#378CB4 Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #378CB4

Not just a swatch — here's how #378CB4 works with other colors. Named schemes with #378CB4 in its natural role, and a note on why the supporting colors balance it.

Coastal Morning Lead · 5 colors

Lead #378CB4 Accent #A6C4C0 Surface #DEDABF Secondary #9AA0A0 Anchor #1F344A

Ocean 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 #378CB4 Surface #14161A Highlight #F4F6F8 Secondary #5A6672 Accent #68B1D6

Ocean 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 Ocean Blue.

Vintage Leather Lead · 5 colors

Lead #378CB4 Secondary #6F5216 Surface #E2DCC0 Accent #385244 Anchor #56233D

Ocean 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 #378CB4 Surface #EEE9D6 Anchor #592247 Accent #E4C2CC Secondary #322B30

Ocean 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 #378CB4 Secondary #97B1C0 Support #969386 Ink #16140F

Ocean 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 Ocean Blue carrying the quiet middle.

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Color Lab

How #378CB4 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 20/100

Cool

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

Softness 51/100

Moderate

Middle-weight — neither delicate nor heavy.

Depth 39/100

Low

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

Naturalness 1/100

Very low

Reads engineered rather than organic — synthetic, digital.

Vintage feel 51/100

Moderate

A faint retro warmth without tipping into sepia.

Luxury 47/100

Moderate

Understated — leans refined without going austere.

Brand distinctiveness 27/100

Low

Quiet and neutral — a supporting tone, not a signature.

UI accent fit 85/100

Very high

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

Surface fit 32/100

Low

Usable as a tinted surface in measured doses.

Print safety 74/100

High

Reproduces faithfully in CMYK — safe for packaging and print.

Pairs with #378CB4

For UI

For branding

For interior

For fashion

People also use #378CB4 with

Medium Aquamarine Cerulean Ginger Platinum 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 4.9:1. Use

Subtle surface Use #D9E7EE for cards and hover fills. Tint 80

Avoid beside #3763B3 — 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 #378CB4 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: #378CB4;
  --color-base-rgb: 55 140 180;
  --color-base-oklch: oklch(60.6% 0.101 232.4);
  --color-50: #F3F9FC;
  --color-100: #DFEFF6;
  --color-200: #C1DEEC;
  --color-300: #95C4DA;
  --color-400: #6DA9C5;
  --color-500: #4C8CA9;
  --color-600: #406D82;
  --color-700: #324F5D;
  --color-800: #24353D;
  --color-900: #172126;
  --color-on-base: #141310;
}

// tailwind.config.js
colors: {
  ocean-blue: {
    50: '#F3F9FC',
    100: '#DFEFF6',
    200: '#C1DEEC',
    300: '#95C4DA',
    400: '#6DA9C5',
    500: '#4C8CA9',
    600: '#406D82',
    700: '#324F5D',
    800: '#24353D',
    900: '#172126',
  },
}

$base: #378CB4;
$base-ink: #141310;
$base-50: #F3F9FC;
$base-100: #DFEFF6;
$base-200: #C1DEEC;
$base-300: #95C4DA;
$base-400: #6DA9C5;
$base-500: #4C8CA9;
$base-600: #406D82;
$base-700: #324F5D;
$base-800: #24353D;
$base-900: #172126;
$base-hover: #2C7090;
$base-subtle: #C5DCE6;

{
    "color": {
        "base": {
            "value": "#378CB4",
            "type": "color"
        },
        "onBase": {
            "value": "#141310",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F3F9FC",
                "type": "color"
            },
            "100": {
                "value": "#DFEFF6",
                "type": "color"
            },
            "200": {
                "value": "#C1DEEC",
                "type": "color"
            },
            "300": {
                "value": "#95C4DA",
                "type": "color"
            },
            "400": {
                "value": "#6DA9C5",
                "type": "color"
            },
            "500": {
                "value": "#4C8CA9",
                "type": "color"
            },
            "600": {
                "value": "#406D82",
                "type": "color"
            },
            "700": {
                "value": "#324F5D",
                "type": "color"
            },
            "800": {
                "value": "#24353D",
                "type": "color"
            },
            "900": {
                "value": "#172126",
                "type": "color"
            }
        }
    }
}

Palettes built on #378CB4

Color Lab

Pairs with #378CB4

UI roles & guardrails

In real applications

Scales

Every model

Export