Skip to content
blue · cool

#643cf5

a balanced, electric blue · cool · closest name: Blue Violet

Token name suggestion: Studio Harbour

RGB
100, 60, 245
HSL
253°, 90%, 60%
CMYK
59, 76, 0, 4
Luminance
0.1253

#643cf5 is a balanced electric blue, 253° on the wheel and 76/100 on the cool side. Put white text on it (5.99:1). As text it scores 5.99:1 on white — safe at any size. Nearest name is Blue Violet, nearest Tailwind family is violet.

hsl(253 90% 60%)rgb(100 60 245)Base step 500AA inkCool

At a glance

Every number on this page in one read: what #643cf5 is made of, how bright it looks, and which way it leans.

Hex
#643cf5
Hue
253°
blue
Saturation
90%
electric
Lightness
60%
balanced
Brightness
96%
HSV value
Perceived
43%
weighted brightness
Luminance
0.1253
WCAG relative
Temperature
Cool
76/100 cool
Color family
Blue
Tone
Electric
Best ink
White
5.99:1
Closest name
Blue Violet
ΔE2000 6.2
Chroma
106.5
LCH, 0–130ish
OKLCH L
0.528
perceptual lightness
Tailwind
violet
500 · ΔE 10
Web-safe
#6633FF
nearest of 216
Where it sits
Hue253° of 360°
Saturation90%
Lightness60%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #643cf5.

Temperature
Warm ← → Cool76% cool

Reads cool. Warm and cool siblings keep the same lightness, so you can swap one in without redoing your contrast maths.

Luminance by channel
Red22%
Green26%
Blue53%

Green carries most of what the eye calls brightness — that is why WCAG weights it 0.7152.

Every format

HEX#643cf5
HEX (8-digit)#643cf5ff
RGBrgb(100, 60, 245)
RGBArgba(100, 60, 245, 1)
HSLhsl(253, 90%, 60%)
HSV / HSBhsv(253, 76%, 96%)
HWBhwb(253 24% 4%)
CMYKcmyk(59%, 76%, 0%, 4%)
LABlab(42.0 62.9 -85.9)
LCHlch(42.0 106.5 306.2)
OKLCHoklch(0.528 0.255 283.3)
XYZ (D65)xyz(23.35, 12.53, 87.56)
Decimal6569205
Display P3color(display-p3 0.392 0.235 0.961)
Web-safe#6633FF

Copy-ready code

every platformclick to select
/* CSS */
color: #643cf5;
background-color: #643cf5;
/* CSS custom property */
--brand: #643cf5;
/* Tailwind (arbitrary) */
class="text-[#643cf5] bg-[#643cf5]"
/* SCSS */
$brand: #643cf5;
/* SwiftUI */
Color(red: 0.392, green: 0.235, blue: 0.961)
/* UIKit */
UIColor(red: 0.392, green: 0.235, blue: 0.961, alpha: 1)
/* Android XML */
<color name="brand">#643CF5</color>
/* Android Compose */
Color(0xFF643CF5)
/* Flutter */
Color(0xFF643CF5)
/* Python / OpenCV (BGR) */
(245, 60, 100)
/* Python / PIL (RGB) */
(100, 60, 245)
/* Java AWT */
new Color(100, 60, 245)
/* .NET */
Color.FromArgb(255, 100, 60, 245)
/* OpenGL / Unity (0–1) */
(0.3922f, 0.2353f, 0.9608f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{100,60,245}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #643cf5 85%, white);
border-color: color-mix(in oklab, #643cf5 40%, transparent);
/* theme-aware in one line */
color: light-dark(#1F0679, #D9D3EE);
/* relative colour syntax */
--hover: hsl(from #643cf5 h s calc(l - 7));

Design tokens

The same ramp in the four formats a team actually needs. Paste one and the whole palette lands with it.

css custom propertiesclick to select
:root {
  --brand-50: #F4F2FD;
  --brand-100: #E9E5FB;
  --brand-200: #CFC3F8;
  --brand-300: #AA94FA;
  --brand-400: #805FF7;
  --brand-500: #643cf5;
  --brand-600: #3C0CE9;
  --brand-700: #320AC2;
  --brand-800: #28089B;
  --brand-900: #200A70;
  --brand-950: #140746;
  --brand: #643cf5;
  --brand-ink: #ffffff;
  --brand-surface: #F6F4FA;
  --brand-border: #C9C0ED;
  --brand-hover: #491AF3;
  --brand-pressed: #390BDE;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #171424;
    --brand-ink: #D9D3EE;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F4F2FD',
        100: '#E9E5FB',
        200: '#CFC3F8',
        300: '#AA94FA',
        400: '#805FF7',
        500: '#643cf5',
        600: '#3C0CE9',
        700: '#320AC2',
        800: '#28089B',
        900: '#200A70',
        950: '#140746',
        DEFAULT: '#643cf5',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F4F2FD,
  '100': #E9E5FB,
  '200': #CFC3F8,
  '300': #AA94FA,
  '400': #805FF7,
  '500': #643cf5,
  '600': #3C0CE9,
  '700': #320AC2,
  '800': #28089B,
  '900': #200A70,
  '950': #140746,
);
$brand-base: #643cf5;
$brand-ink: #ffffff;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#F4F2FD", "$type": "color" },
      "100": { "$value": "#E9E5FB", "$type": "color" },
      "200": { "$value": "#CFC3F8", "$type": "color" },
      "300": { "$value": "#AA94FA", "$type": "color" },
      "400": { "$value": "#805FF7", "$type": "color" },
      "500": { "$value": "#643cf5", "$type": "color" },
      "600": { "$value": "#3C0CE9", "$type": "color" },
      "700": { "$value": "#320AC2", "$type": "color" },
      "800": { "$value": "#28089B", "$type": "color" },
      "900": { "$value": "#200A70", "$type": "color" },
      "950": { "$value": "#140746", "$type": "color" }
    },
    "brandInk": { "$value": "#ffffff", "$type": "color" }
  }
}

Best text color

Only one of black and white can be right. This is the one, with the number that proves it.

Readable at a glance#ffffff on #643cf5 · 5.99:1
Use #ffffffAA at every size, AAA for large text only.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 5.99:1 · recommended
AA pass · AA large pass · AAA fail
Aa
Black text · 3.51:1
AA fail · AA large pass · AAA fail
Reading the other direction: #643cf5 as text scores 5.99:1 on white and 3.51:1 on black.
Best tinted ink on it, if plain black or white feels flat: #ECE7FE at 4.97:1.

Make it accessible

A contrast checker tells you that you failed. This tells you what to ship instead — same hue, same saturation, lightness moved only as far as WCAG demands.

The quick fox
#643cf5 · 5.99:1
AA on whitealready passes
#643cf5
The quick fox
#5124F4 · 7.22:1
AAA on white−5% L
#5124F4
The quick fox
#7B59F6 · 4.60:1
AA on black+6% L
#7B59F6
The quick fox
#9E85F9 · 7.18:1
AAA on black+15% L
#9E85F9

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #643CF5 is enough for headings on white. Non-text elements such as icons, chart strokes and focus rings also sit at 3:1 under WCAG 2.2 (1.4.11).

Accessibility — WCAG contrast

Aa
#643cf5 on white: 5.99:1
AA ✓ pass · AA-large · AAA
Aa
#643cf5 on black: 3.51:1
AA ✗ fail · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #643cf5 as text on that neutral, and that neutral as text on #643cf5.

NeutralRatioBoth directions
White5.99:1AaAa
Slate 505.72:1AaAa
Slate 1005.47:1AaAa
Slate 2004.86:1AaAa
Slate 3004.03:1AaAa
Slate 4002.34:1AaAa
Slate 5001.26:1AaAa
Slate 6001.27:1AaAa
Slate 7001.73:1AaAa
Slate 8002.44:1AaAa
Slate 9002.98:1AaAa
Black3.51:1AaAa
Colour vision deficiency
true color
protanopia · #0069FA
deuteranopia · #005DF2
tritanopia · #007297

Roughly one man in twelve has some form of colour vision deficiency. If any of the three panels above is hard to tell apart from a neighbouring colour in your palette, add a shape, an icon or a label so the meaning does not rest on hue alone.

Color scale — 50 to 950

A Tailwind-shaped ramp built around this exact hex. #643cf5 is pinned to step 500; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#F4F2FD
#E9E5FB
#CFC3F8
#AA94FA
#805FF7
#643cf5
#3C0CE9
#320AC2
#28089B
#200A70
#140746
Base = 500Lightest = 50 · #F4F2FDDarkest = 950 · #140746Text step on white = 500
Perceptual ramp — OKLCH

The same eleven steps expressed in OKLCH, where equal lightness numbers actually look equally spaced. HSL ramps go muddy in the yellows and washed out in the blues; this one does not. Modern browsers render it natively — the hex ramp above is the fallback.

50100200300400500600700800900950
oklch tokensclick to select
:root {
  --brand-50: oklch(0.97 0.064 283.3);
  --brand-100: oklch(0.94 0.102 283.3);
  --brand-200: oklch(0.88 0.153 283.3);
  --brand-300: oklch(0.80 0.199 283.3);
  --brand-400: oklch(0.72 0.234 283.3);
  --brand-500: oklch(0.64 0.255 283.3);
  --brand-600: oklch(0.56 0.255 283.3);
  --brand-700: oklch(0.48 0.239 283.3);
  --brand-800: oklch(0.40 0.214 283.3);
  --brand-900: oklch(0.32 0.178 283.3);
  --brand-950: oklch(0.24 0.140 283.3);
}

Colors that work with #643cf5

Not a palette — a role sheet. Each swatch answers one question you will hit while building the component.

Text on it#ffffff
White wins here
Surface#F6F4FA
Tinted page background
Border#C9C0ED
Hairlines and dividers
Muted text#5C4B9B
Captions on the surface
Accent#C6C006
Second voice, not a rival
Dark variant#1F0679
Hover, pressed, headers
Light variant#ECE7FE
Selected rows, tints
Dark surface#171424
Dark-mode background
Hover#491AF3
One step down in lightness
Pressed#390BDE
Two steps down
Disabled#CBC6DB
Chroma pulled out
Focus ring#6E46FF
Offset from the fill so it reads
Light mode
Everything in its place

Surface, border, heading and body all derive from this one hue, so the screen stays coherent without a second palette.

Primary actionSecondaryBadge
Dark mode
Same hue, inverted

Lightness flips, hue holds. The accent stays the anchor in both themes.

Primary actionSecondaryAccent

In real components

The same eight roles, wired into the interface patterns you will actually build with them. Every state below is a computed value, not a mock-up.

Buttons and states
Save changesHoverPressedDisabled
OutlineSubtleLinkFocused
Form field
you@company.com

Focus ring uses the light variant so the field still reads as one shape.

Send me product updates
Notice
Your export is ready

The file stays available for seven days. Download it before it expires.

NewBetaDraft
Data
Storage used68%
Acme LtdActive
NorthwindTrial
GlobexActive

How to use #643cf5

Derived from its contrast, chroma and lightness — not from taste.

Works well for
  • Body text and links on white
  • Primary buttons and calls to action
  • Focus rings, active and selected states
  • Brand accents, badges and data highlights
  • Chart series and data categories
Use with care
  • Full-page backgrounds — tiring over long sessions
  • Pairing with a same-lightness hue — edges vibrate
Minimum size as text on white
Any size
Safe as a fill behind white type
Yes
Safe as a 1px border on white
Yes

Meaning and mood

What a colour in this family tends to signal, and how this particular chroma and lightness change the reading.

trustedcalmcompetentcorporate

The default of institutions for a reason: blue is read as stable and safe across nearly every culture that has been surveyed.

At this chroma the association is amplified — it will dominate anything placed beside it, so give it space and use it sparingly. The mid lightness keeps it versatile in both themes.

Worth knowing

It is also the most crowded hue on the web. Distinctiveness has to come from your other choices.

Reads as
  • FormalityLow
  • EnergyHigh
  • Weight40/100
  • TemperatureCool
  • ApproachabilityReserved

Colour associations are cultural and vary by market. Treat these as a starting point for a conversation with your audience, not a finding about them.

Similar colors

One move away from this hex in each direction. Every swatch is its own page.

Color relationships

The wheel positions with their names attached, so you can grab the one you actually need.

Complementary#CDF53C
Analogous left#3C70F5
Analogous right#C13CF5
Split-complement 1#F5C13C
Split-complement 2#70F53C
Triadic 1#F5643C
Triadic 2#3CF564
Tetradic#F53C70
On the wheel
Base+30°−30°+120°+240°+180°253°

#643cf5 sits at 253°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red39.2%
Green23.5%
Blue96.1%
R · 0–255
100
0x64
G · 0–255
60
0x3c
B · 0–255
245
0xf5

CMYK percentages

Cyan59.2%
Magenta75.5%
Yellow0.0%
Key (black)3.9%

Total ink coverage is 139%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#643cf5 text on a black background

contrast 3.51:1

Card sample

#643cf5 text on a white background

contrast 5.99:1

Card sample

#643cf5 on grey

5.47:1

#643cf5 on its own surface

5.49:1

#643cf5 on its dark surface

3.02:1

CSS3 live lab

Text font color

The quick brown fox

color: #643cf5;
Background color
Panel with #643cf5 background
background-color: #643cf5;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #643cf5;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(100, 60, 245, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(100, 60, 245, 0.45);
Border & gradient
Gradient panel
border: 3px solid #643cf5;
background: linear-gradient(135deg, #643cf5, #DF3CF5);
Gradient text

Gradient headline

background: linear-gradient(90deg, #643cf5, #F53CDC);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #643cf5;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #643cf5;
caret-color: #643cf5;
Left rule
Pull quote or callout
border-left: 4px solid #643cf5;
Ring + tint
Selected chip
background: #ECE7FE;
box-shadow: inset 0 0 0 2px #643cf5;
Conic badge
68%
background: conic-gradient(#643cf5 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #643cf5 over white; the bottom row is the same alpha over a checkerboard, so you can see what survives on a photo or a video.

Bottom row of hexes is the flattened result over white — use those when a design tool refuses transparency, or when you need a solid fallback.

alpha in every syntaxclick to select
rgba(100, 60, 245, 0.5)
rgb(100 60 245 / 50%)
#643cf580
hsl(253 90% 60% / 50%)
color-mix(in srgb, #643cf5 50%, transparent)
Alpha8-digit hexFlat on white
10%#643cf51a#F0ECFE
20%#643cf533#E0D8FD
40%#643cf566#C1B1FB
60%#643cf599#A28AF9
80%#643cf5cc#8363F7

Gradients from #643cf5

Six recipes, each built from this hex and shown with the exact CSS that produced it.

Elevation
Same hue, three lightnesses — safe anywhere
background: linear-gradient(135deg, #9276F8, #643cf5 45%, #1F0679);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #643cf5, #EC1FF3);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #643cf5, #CDF53C);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #A993F9 0%, #643cf5 45%, #1F0679 100%);
Soft wash
Section backgrounds that stay readable
background: linear-gradient(180deg, #F6F4FA, #ffffff);
Mesh
Ambient background, no image weight
background: radial-gradient(60% 60% at 15% 20%, #6D9FF7 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #D759F6 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #1F0679 0%, transparent 65%), #643cf5;

Monochromatic scale

Palettes built from #643cf5

Shades — darker

Tints — lighter

Tones — desaturated

Color harmonies

Nearest named colors

Ranked with CIEDE2000 across all 139 CSS keywords. Under ΔE 2 the eye stops telling them apart; over ΔE 10 they are plainly different colors.

#643cf5 in the real world

Where a color in this family tends to land, and the interface roles it is usually asked to play.

Industries
TechnologyFinanceHealthcareEnterprise SaaS
Common UI roles
ButtonsLinksFocus statesCharts
Print note

Sits outside most CMYK gamuts — expect a duller press result, or specify a spot ink.

On screens

Holds up across typical panel gamma. Still worth checking on an uncalibrated laptop, where mid-tones shift most.

In dark mode

Too dim on dark surfaces at 3.51:1 — lift it to #7B59F6 for body text, or reserve it for fills.

Explore nearby colors

Small, deliberate steps away from this hex — useful when you are hunting for the version of a colour that finally feels right.

#643cf5, answered

What color is #643cf5?

#643cf5 is a balanced electric blue, closest to Blue Violet (ΔE2000 6.2). It sits at 253° on the hue wheel with 90% saturation and 60% lightness, which reads as cool.

What is the RGB value of #643cf5?

rgb(100, 60, 245) — 100 red, 60 green and 245 blue out of 255, or 39.2% / 23.5% / 96.1% by channel.

What is #643cf5 in HSL and HSV?

hsl(253, 90%, 60%) and hsv(253, 76%, 96%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #643cf5 a light or a dark color?

It is a dark color. Relative luminance is 0.1253 and perceived brightness is 43%, so white text on it reaches 5.99:1.

Should I use black or white text on #643cf5?

White. It scores 5.99:1 against #643cf5, versus 3.51:1 for black — AA at any size.

Is #643cf5 accessible on a white background?

#643cf5 on white scores 5.99:1, which clears AA at every size but not AAA.

What is the complementary color of #643cf5?

#CDF53C sits directly opposite on the wheel. Softer options are the split-complements #F5C13C and #70F53C, which give the same contrast with far less vibration.

What colors go well with #643cf5?

For interface work: #F6F4FA as the surface, #C9C0ED for borders, #5C4B9B for secondary text, #C6C006 as an accent and #1F0679 for hover and pressed states. For a palette, the analogous pair #3C70F5 and #C13CF5 stays calm, while #CDF53C is the loudest partner.

What is #643cf5 in CMYK for printing?

cmyk(59%, 76%, 0%, 4%). This is a screen-to-ink approximation — a color this saturated sits outside most CMYK gamuts and will print duller than it looks here.

Is #643cf5 warm or cool?

Cool — it scores 76 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #A83CF5; nudged cooler, #3A56F7.

Which Tailwind color is closest to #643cf5?

The violet family — its 500 step is #8b5cf6, ΔE2000 10 away. That is a visible difference, so define #643cf5 as a custom token rather than reaching for the built-in.

How do I use #643cf5 in Tailwind CSS?

Inline it as an arbitrary value with bg-[#643cf5] or text-[#643cf5], or register the whole ramp under theme.extend.colors.brand so you get bg-brand-500 and friends. The generated 50–950 scale on this page is ready to paste into your config.

What is #643cf5 with 50% opacity?

rgba(100, 60, 245, 0.5), or #643cf580 in eight-digit hex. Over white that composites to #B29EFA; over black, #321E7B.

Is #643cf5 a web-safe color?

No. The nearest web-safe colour is #6633FF, ΔE2000 1.6 away. The palette only matters for legacy displays and some email clients now.

What does the color #643cf5 mean?

As a blue, it reads trusted, calm, competent. The default of institutions for a reason: blue is read as stable and safe across nearly every culture that has been surveyed. At this chroma the effect is amplified — it will dominate whatever sits beside it.

What gradient works with #643cf5?

The safest is same-hue elevation: linear-gradient(135deg, #9276F8, #643cf5 45%, #1F0679). For more colour, a short hue run to #EC1FF3 keeps it rich without turning muddy.

Work with #643cf5 in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #643cf5 at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.