What color is #397DE4?

#397DE4 is a medium, vivid blue. In RGB it is rgb(57, 125, 228), and in HSL hsl(216, 76%, 56%).

Is #397DE4 accessible as text?

On white, #397DE4 has a contrast ratio of 4.02:1 (fails WCAG AA for body text); on black it is 5.23:1 (passes). For text placed on #397DE4, use black for the best readability.

What is the closest Tailwind color to #397DE4?

The nearest Tailwind CSS token is blue-500 (#2B7FFF).

What colors go well with #397DE4?

#397DE4 pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #E4A03A. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #397DE4 below.

Is #397DE4 good for buttons?

#397DE4 works well for buttons and highlights, but use black text on #397DE4 — white text only reaches 4.02:1, below the 4.5:1 needed for normal-size labels.

Is #397DE4 the same as CSS royalblue?

No — #397DE4 is not the CSS named color royalblue, but royalblue (#4169E1) is the closest CSS named color.

#397DE4 Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #397DE4

Not just a swatch — here's how #397DE4 works with other colors. Named schemes with #397DE4 in its natural role, and a note on why the supporting colors balance it.

Coastal Morning Lead · 5 colors

Lead #397DE4 Accent #A5C4C1 Surface #DDDBBF Secondary #9AA0A1 Anchor #20344A

Signal 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 #397DE4 Surface #14161A Highlight #F4F6F8 Secondary #5A6672 Accent #66A4FF

Signal 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 Signal Blue.

Vintage Leather Lead · 5 colors

Lead #397DE4 Secondary #7F4536 Surface #E1DDC1 Accent #375246 Anchor #57223A

Signal 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 #397DE4 Surface #EDE9D6 Anchor #5A2144 Accent #E4C2CA Secondary #322B2F

Signal 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 #397DE4 Secondary #94ACD1 Support #9D8F89 Ink #16140F

Signal 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 Signal Blue carrying the quiet middle.

Build a working theme in the generator →

Color Lab

How #397DE4 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 6/100

Cool

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

Softness 41/100

Moderate

Middle-weight — neither delicate nor heavy.

Depth 42/100

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 32/100

Low

A faint retro warmth without tipping into sepia.

Luxury 44/100

Moderate

Understated — leans refined without going austere.

Brand distinctiveness 46/100

Moderate

Recognisable but shares space with nearby hues.

UI accent fit 89/100

Very high

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

Surface fit 17/100

Very low

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

Print safety 66/100

High

Prints close, with a slight loss of vibrancy.

Pairs with #397DE4

For UI

For branding

For interior

For fashion

People also use #397DE4 with

Turquoise Han Purple Butterscotch 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 4.6:1. Use

Subtle surface Use #DCE6F5 for cards and hover fills. Tint 80

Avoid beside #3A45E4 — 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 #397DE4 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: #397DE4;
  --color-base-rgb: 57 125 228;
  --color-base-oklch: oklch(60.0% 0.171 258.7);
  --color-50: #F1F6FE;
  --color-100: #DAE7FB;
  --color-200: #B7D0F5;
  --color-300: #87AEE9;
  --color-400: #5A8CD8;
  --color-500: #376DBD;
  --color-600: #325790;
  --color-700: #294166;
  --color-800: #1E2D43;
  --color-900: #141D29;
  --color-on-base: #141310;
}

// tailwind.config.js
colors: {
  signal-blue: {
    50: '#F1F6FE',
    100: '#DAE7FB',
    200: '#B7D0F5',
    300: '#87AEE9',
    400: '#5A8CD8',
    500: '#376DBD',
    600: '#325790',
    700: '#294166',
    800: '#1E2D43',
    900: '#141D29',
  },
}

$base: #397DE4;
$base-ink: #141310;
$base-50: #F1F6FE;
$base-100: #DAE7FB;
$base-200: #B7D0F5;
$base-300: #87AEE9;
$base-400: #5A8CD8;
$base-500: #376DBD;
$base-600: #325790;
$base-700: #294166;
$base-800: #1E2D43;
$base-900: #141D29;
$base-hover: #1B61C9;
$base-subtle: #CAD9F1;

{
    "color": {
        "base": {
            "value": "#397DE4",
            "type": "color"
        },
        "onBase": {
            "value": "#141310",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F1F6FE",
                "type": "color"
            },
            "100": {
                "value": "#DAE7FB",
                "type": "color"
            },
            "200": {
                "value": "#B7D0F5",
                "type": "color"
            },
            "300": {
                "value": "#87AEE9",
                "type": "color"
            },
            "400": {
                "value": "#5A8CD8",
                "type": "color"
            },
            "500": {
                "value": "#376DBD",
                "type": "color"
            },
            "600": {
                "value": "#325790",
                "type": "color"
            },
            "700": {
                "value": "#294166",
                "type": "color"
            },
            "800": {
                "value": "#1E2D43",
                "type": "color"
            },
            "900": {
                "value": "#141D29",
                "type": "color"
            }
        }
    }
}

Palettes built on #397DE4

Color Lab

Pairs with #397DE4

UI roles & guardrails

In real applications

Scales

Every model

Export