What color is #3F42E2?

#3F42E2 is a medium, vivid blue-violet. In RGB it is rgb(63, 66, 226), and in HSL hsl(239, 74%, 57%).

Is #3F42E2 accessible as text?

On white, #3F42E2 has a contrast ratio of 6.80:1 (passes WCAG AA for body text); on black it is 3.09:1 (fails). For text placed on #3F42E2, use white for the best readability.

What is the closest Tailwind color to #3F42E2?

The nearest Tailwind CSS token is blue-700 (#1447E6).

What colors go well with #3F42E2?

#3F42E2 pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #E2E040. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #3F42E2 below.

Is #3F42E2 good for buttons?

#3F42E2 works well for buttons and highlights, but use white text on #3F42E2 — black text only reaches 3.09:1, below the 4.5:1 needed for normal-size labels.

Is #3F42E2 the same as CSS royalblue?

No — #3F42E2 is not the CSS named color royalblue, but royalblue (#4169E1) is the closest CSS named color.

#3F42E2 Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #3F42E2

Not just a swatch — here's how #3F42E2 works with other colors. Named schemes with #3F42E2 in its natural role, and a note on why the supporting colors balance it.

Tech Product Signal · 5 colors

Signal #3F42E2 Surface #14161A Highlight #F4F6F8 Secondary #5B6672 Accent #5E71FF

Neon 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 Neon Blue.

Coastal Morning Lead · 5 colors

Lead #3F42E2 Accent #A5C4C2 Surface #EAD5C0 Secondary #9AA0A1 Anchor #21344A

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

Berry & Cream Lead · 5 colors

Lead #3F42E2 Surface #F6E5D8 Anchor #5B2143 Accent #E5C2C9 Secondary #322B2F

Neon 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 #3F42E2 Secondary #7987BC Support #9D8F88 Ink #18140F

Neon 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 Neon Blue carrying the quiet middle.

Sunset Warmth Glow · 5 colors

Glow #3F42E2 Secondary #E86A73 Accent #F6924F Anchor #573B58 Surface #F7E7D7

Neon Blue glows at the center of this sunset palette, joined by coral and gold, deepened by a plum anchor and cooled with cream.

Build a working theme in the generator →

Color Lab

How #3F42E2 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 28/100

Low

Firm and assertive — carries weight and contrast.

Depth 56/100

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 13/100

Very low

Clean and current — no dusty, aged cast.

Luxury 49/100

Moderate

Understated — leans refined without going austere.

Brand distinctiveness 90/100

Very high

Bold and ownable — memorable as a primary brand color.

UI accent fit 68/100

High

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

Surface fit 8/100

Very low

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

Print safety 61/100

High

Prints close, with a slight loss of vibrancy.

Pairs with #3F42E2

For UI

For branding

For interior

For fashion

People also use #3F42E2 with

Picton Blue Dark Orchid Pear Gainsboro Prussian Blue

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 6.8:1. Use

Subtle surface Use #DDDEF5 for cards and hover fills. Tint 80

Avoid beside #7440E2 — 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 #3F42E2 at work across the surfaces designers actually ship.

Website / UI

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Build faster.

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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: #3F42E2;
  --color-base-rgb: 63 66 226;
  --color-base-oklch: oklch(49.2% 0.234 272.9);
  --color-50: #F1F1FE;
  --color-100: #DBDBFB;
  --color-200: #B8B9F4;
  --color-300: #8889E7;
  --color-400: #5C5ED6;
  --color-500: #393BBC;
  --color-600: #33348F;
  --color-700: #2A2B65;
  --color-800: #1F1F42;
  --color-900: #151529;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  neon-blue: {
    50: '#F1F1FE',
    100: '#DBDBFB',
    200: '#B8B9F4',
    300: '#8889E7',
    400: '#5C5ED6',
    500: '#393BBC',
    600: '#33348F',
    700: '#2A2B65',
    800: '#1F1F42',
    900: '#151529',
  },
}

$base: #3F42E2;
$base-ink: #FFFFFF;
$base-50: #F1F1FE;
$base-100: #DBDBFB;
$base-200: #B8B9F4;
$base-300: #8889E7;
$base-400: #5C5ED6;
$base-500: #393BBC;
$base-600: #33348F;
$base-700: #2A2B65;
$base-800: #1F1F42;
$base-900: #151529;
$base-hover: #1E21CA;
$base-subtle: #CCCCF1;

{
    "color": {
        "base": {
            "value": "#3F42E2",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F1F1FE",
                "type": "color"
            },
            "100": {
                "value": "#DBDBFB",
                "type": "color"
            },
            "200": {
                "value": "#B8B9F4",
                "type": "color"
            },
            "300": {
                "value": "#8889E7",
                "type": "color"
            },
            "400": {
                "value": "#5C5ED6",
                "type": "color"
            },
            "500": {
                "value": "#393BBC",
                "type": "color"
            },
            "600": {
                "value": "#33348F",
                "type": "color"
            },
            "700": {
                "value": "#2A2B65",
                "type": "color"
            },
            "800": {
                "value": "#1F1F42",
                "type": "color"
            },
            "900": {
                "value": "#151529",
                "type": "color"
            }
        }
    }
}

Palettes built on #3F42E2

Color Lab

Pairs with #3F42E2

UI roles & guardrails

In real applications

Scales

Every model

Export