What color is #6658CF?

#6658CF is a medium indigo. In RGB it is rgb(102, 88, 207), and in HSL hsl(247, 55%, 58%).

Is #6658CF accessible as text?

On white, #6658CF has a contrast ratio of 5.44:1 (passes WCAG AA for body text); on black it is 3.86:1 (fails). For text placed on #6658CF, use white for the best readability.

What is the closest Tailwind color to #6658CF?

The nearest Tailwind CSS token is indigo-500 (#615FFF).

What colors go well with #6658CF?

#6658CF pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #C1CF59. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #6658CF below.

Is #6658CF good for buttons?

#6658CF works well for buttons and highlights, but use white text on #6658CF — black text only reaches 3.86:1, below the 4.5:1 needed for normal-size labels.

Is #6658CF the same as CSS slateblue?

No — #6658CF is not the CSS named color slateblue, but slateblue (#6A5ACD) is the closest CSS named color.

#6658CF Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #6658CF

Not just a swatch — here's how #6658CF works with other colors. Named schemes with #6658CF in its natural role, and a note on why the supporting colors balance it.

Coastal Morning Lead · 5 colors

Lead #6658CF Accent #A5C4C3 Surface #EAD5BF Secondary #9AA0A1 Anchor #22334A

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

Vintage Leather Lead · 5 colors

Lead #6658CF Secondary #7E4533 Surface #EDD7C2 Accent #365247 Anchor #582238

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.

Modern Café Dominant · 5 colors

Dominant #6658CF Anchor #3B2923 Surface #F3E1D2 Accent #759F7C Secondary #3C3734

Slate Blue anchors this café scheme as the warm mid-tone, lifted by latte cream and a muted sage accent and grounded by espresso brown and a warm charcoal.

Berry & Cream Lead · 5 colors

Lead #6658CF Surface #F5E5D7 Anchor #5B2142 Accent #E5C2C8 Secondary #332B2F

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 #6658CF Secondary #9393BD Support #9D9088 Ink #18140F

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 Slate Blue carrying the quiet middle.

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Color Lab

How #6658CF 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 21/100

Cool

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

Softness 37/100

Low

Middle-weight — neither delicate nor heavy.

Depth 49/100

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 35/100

Low

A faint retro warmth without tipping into sepia.

Luxury 49/100

Moderate

Understated — leans refined without going austere.

Brand distinctiveness 48/100

Moderate

Recognisable but shares space with nearby hues.

UI accent fit 95/100

Very high

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

Surface fit 11/100

Very low

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

Print safety 74/100

High

Reproduces faithfully in CMYK — safe for packaging and print.

Pairs with #6658CF

For UI

For branding

For interior

For fashion

People also use #6658CF with

Iceberg Medium Orchid Citrine 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 5.4:1. Use

Subtle surface Use #E3E1F2 for cards and hover fills. Tint 80

Avoid beside #8E59CF — 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 #6658CF 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: #6658CF;
  --color-base-rgb: 102 88 207;
  --color-base-oklch: oklch(53.8% 0.177 284.1);
  --color-50: #F4F3FC;
  --color-100: #E2DFF6;
  --color-200: #C5C0ED;
  --color-300: #9C94DB;
  --color-400: #766BC7;
  --color-500: #554AAB;
  --color-600: #473F83;
  --color-700: #36315E;
  --color-800: #26233E;
  --color-900: #191726;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  slate-blue: {
    50: '#F4F3FC',
    100: '#E2DFF6',
    200: '#C5C0ED',
    300: '#9C94DB',
    400: '#766BC7',
    500: '#554AAB',
    600: '#473F83',
    700: '#36315E',
    800: '#26233E',
    900: '#191726',
  },
}

$base: #6658CF;
$base-ink: #FFFFFF;
$base-50: #F4F3FC;
$base-100: #E2DFF6;
$base-200: #C5C0ED;
$base-300: #9C94DB;
$base-400: #766BC7;
$base-500: #554AAB;
$base-600: #473F83;
$base-700: #36315E;
$base-800: #26233E;
$base-900: #191726;
$base-hover: #4435B7;
$base-subtle: #D5D1EC;

{
    "color": {
        "base": {
            "value": "#6658CF",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F4F3FC",
                "type": "color"
            },
            "100": {
                "value": "#E2DFF6",
                "type": "color"
            },
            "200": {
                "value": "#C5C0ED",
                "type": "color"
            },
            "300": {
                "value": "#9C94DB",
                "type": "color"
            },
            "400": {
                "value": "#766BC7",
                "type": "color"
            },
            "500": {
                "value": "#554AAB",
                "type": "color"
            },
            "600": {
                "value": "#473F83",
                "type": "color"
            },
            "700": {
                "value": "#36315E",
                "type": "color"
            },
            "800": {
                "value": "#26233E",
                "type": "color"
            },
            "900": {
                "value": "#191726",
                "type": "color"
            }
        }
    }
}

Palettes built on #6658CF

Color Lab

Pairs with #6658CF

UI roles & guardrails

In real applications

Scales

Every model

Export