What color is #313C8F?

#313C8F is a dark blue-violet. In RGB it is rgb(49, 60, 143), and in HSL hsl(233, 49%, 38%).

Is #313C8F accessible as text?

On white, #313C8F has a contrast ratio of 9.66:1 (passes WCAG AA for body text); on black it is 2.17:1 (fails). For text placed on #313C8F, use white for the best readability.

What is the closest Tailwind color to #313C8F?

The nearest Tailwind CSS token is blue-900 (#1C398E).

What colors go well with #313C8F?

#313C8F pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #908531. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #313C8F below.

Is #313C8F good for buttons?

#313C8F works well for buttons and highlights, but use white text on #313C8F — black text only reaches 2.17:1, below the 4.5:1 needed for normal-size labels.

Is #313C8F the same as CSS darkslateblue?

No — #313C8F is not the CSS named color darkslateblue, but darkslateblue (#483D8B) is the closest CSS named color.

#313C8F Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #313C8F

Not just a swatch — here's how #313C8F works with other colors. Named schemes with #313C8F in its natural role, and a note on why the supporting colors balance it.

Coastal Morning Lead · 5 colors

Lead #313C8F Accent #A5C4C2 Surface #EAD5C0 Secondary #9AA0A1 Anchor #21344A

Dark Slate 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 #313C8F Surface #14161A Highlight #F4F6F8 Secondary #5B6672 Accent #5161AE

Dark Slate 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 Dark Slate Blue.

Vintage Leather Lead · 5 colors

Lead #313C8F Secondary #7F4535 Surface #EED7C2 Accent #365247 Anchor #582239

Dark Slate 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 #313C8F Surface #F6E5D8 Anchor #5B2143 Accent #E5C2C9 Secondary #322B2F

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

Minimal Editorial Surface · 5 colors

Surface #F8F4EF Accent #313C8F Secondary #646D8A Support #9D8F88 Ink #18140F

Dark Slate 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 Dark Slate Blue carrying the quiet middle.

Build a working theme in the generator →

Color Lab

How #313C8F 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 32/100

Low

Firm and assertive — carries weight and contrast.

Depth 62/100

High

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

Naturalness 0/100

Very low

Reads engineered rather than organic — synthetic, digital.

Vintage feel 37/100

Low

A faint retro warmth without tipping into sepia.

Luxury 65/100

High

Restrained and premium — deep, quiet, high-end packaging and fashion.

Brand distinctiveness 37/100

Low

Recognisable but shares space with nearby hues.

UI accent fit 74/100

High

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

Surface fit 18/100

Very low

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

Print safety 77/100

High

Reproduces faithfully in CMYK — safe for packaging and print.

Pairs with #313C8F

For UI

For branding

For interior

For fashion

People also use #313C8F with

Steel Blue Rebecca Purple Olive Gainsboro Prussian Blue

UI roles & guardrails

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

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 9.7:1. Use

Subtle surface Use #D4D7EB for cards and hover fills. Tint 80

Avoid beside #463190 — 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 #313C8F at work across the surfaces designers actually ship.

Website / UI

Northwind Sign up

Build faster.

A working theme, generated in seconds.

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: #313C8F;
  --color-base-rgb: 49 60 143;
  --color-base-oklch: oklch(39.8% 0.137 272.8);
  --color-50: #F3F4FB;
  --color-100: #E0E2F5;
  --color-200: #C2C7EA;
  --color-300: #989FD7;
  --color-400: #707AC2;
  --color-500: #4F59A6;
  --color-600: #424A7F;
  --color-700: #34385B;
  --color-800: #25273C;
  --color-900: #181A25;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  dark-slate-blue: {
    50: '#F3F4FB',
    100: '#E0E2F5',
    200: '#C2C7EA',
    300: '#989FD7',
    400: '#707AC2',
    500: '#4F59A6',
    600: '#424A7F',
    700: '#34385B',
    800: '#25273C',
    900: '#181A25',
  },
}

$base: #313C8F;
$base-ink: #FFFFFF;
$base-50: #F3F4FB;
$base-100: #E0E2F5;
$base-200: #C2C7EA;
$base-300: #989FD7;
$base-400: #707AC2;
$base-500: #4F59A6;
$base-600: #424A7F;
$base-700: #34385B;
$base-800: #25273C;
$base-900: #181A25;
$base-hover: #283074;
$base-subtle: #BEC2E1;

{
    "color": {
        "base": {
            "value": "#313C8F",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F3F4FB",
                "type": "color"
            },
            "100": {
                "value": "#E0E2F5",
                "type": "color"
            },
            "200": {
                "value": "#C2C7EA",
                "type": "color"
            },
            "300": {
                "value": "#989FD7",
                "type": "color"
            },
            "400": {
                "value": "#707AC2",
                "type": "color"
            },
            "500": {
                "value": "#4F59A6",
                "type": "color"
            },
            "600": {
                "value": "#424A7F",
                "type": "color"
            },
            "700": {
                "value": "#34385B",
                "type": "color"
            },
            "800": {
                "value": "#25273C",
                "type": "color"
            },
            "900": {
                "value": "#181A25",
                "type": "color"
            }
        }
    }
}

Palettes built on #313C8F

Color Lab

Pairs with #313C8F

UI roles & guardrails

In real applications

Scales

Every model

Export