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red · warm

#ed0421

a balanced, electric red · warm · closest name: Red

Token name suggestion: Studio Ember

RGB
237, 4, 33
HSL
353°, 97%, 47%
CMYK
0, 98, 86, 7
Luminance
0.1820

#ed0421 is a balanced electric red, 353° on the wheel and 21/100 on the cool side. Put black text on it (4.64:1). As text it scores 4.53:1 on white — safe at any size. Nearest name is Red, nearest Tailwind family is red.

hsl(353 97% 47%)rgb(237 4 33)Base step 600AA inkWarm

At a glance

Every number on this page in one read: what #ed0421 is made of, how bright it looks, and which way it leans.

Hex
#ed0421
Hue
353°
red
Saturation
97%
electric
Lightness
47%
balanced
Brightness
93%
HSV value
Perceived
51%
weighted brightness
Luminance
0.1820
WCAG relative
Temperature
Warm
21/100 cool
Color family
Red
Tone
Electric
Best ink
Black
4.64:1
Closest name
Red
ΔE2000 6.1
Chroma
92.1
LCH, 0–130ish
OKLCH L
0.596
perceptual lightness
Tailwind
red
500 · ΔE 6.7
Web-safe
#FF0033
nearest of 216
Where it sits
Hue353° of 360°
Saturation97%
Lightness47%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #ed0421.

Temperature
Warm ← → Cool21% cool

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

Luminance by channel
Red99%
Green0%
Blue1%

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

Every format

HEX#ed0421
HEX (8-digit)#ed0421ff
RGBrgb(237, 4, 33)
RGBArgba(237, 4, 33, 1)
HSLhsl(353, 97%, 47%)
HSV / HSBhsv(353, 98%, 93%)
HWBhwb(353 2% 7%)
CMYKcmyk(0%, 98%, 86%, 7%)
LABlab(49.8 75.8 52.3)
LCHlch(49.8 92.1 34.6)
OKLCHoklch(0.596 0.241 26.2)
XYZ (D65)xyz(35.25, 18.21, 3.10)
Decimal15533089
Display P3color(display-p3 0.929 0.016 0.129)
Web-safe#FF0033

Copy-ready code

every platformclick to select
/* CSS */
color: #ed0421;
background-color: #ed0421;
/* CSS custom property */
--brand: #ed0421;
/* Tailwind (arbitrary) */
class="text-[#ed0421] bg-[#ed0421]"
/* SCSS */
$brand: #ed0421;
/* SwiftUI */
Color(red: 0.929, green: 0.016, blue: 0.129)
/* UIKit */
UIColor(red: 0.929, green: 0.016, blue: 0.129, alpha: 1)
/* Android XML */
<color name="brand">#ED0421</color>
/* Android Compose */
Color(0xFFED0421)
/* Flutter */
Color(0xFFED0421)
/* Python / OpenCV (BGR) */
(33, 4, 237)
/* Python / PIL (RGB) */
(237, 4, 33)
/* Java AWT */
new Color(237, 4, 33)
/* .NET */
Color.FromArgb(255, 237, 4, 33)
/* OpenGL / Unity (0–1) */
(0.9294f, 0.0157f, 0.1294f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{237,4,33}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #ed0421 85%, white);
border-color: color-mix(in oklab, #ed0421 40%, transparent);
/* theme-aware in one line */
color: light-dark(#7D0212, #EED3D6);
/* relative colour syntax */
--hover: hsl(from #ed0421 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: #FDF1F3;
  --brand-100: #FCE4E7;
  --brand-200: #FBC1C8;
  --brand-300: #FD919E;
  --brand-400: #FC596E;
  --brand-500: #FB223D;
  --brand-600: #ed0421;
  --brand-700: #C9031C;
  --brand-800: #A10316;
  --brand-900: #740714;
  --brand-950: #48040D;
  --brand: #ed0421;
  --brand-ink: #000000;
  --brand-surface: #FAF4F5;
  --brand-border: #EDC0C5;
  --brand-hover: #CA031C;
  --brand-pressed: #A70317;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #241416;
    --brand-ink: #EED3D6;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#FDF1F3',
        100: '#FCE4E7',
        200: '#FBC1C8',
        300: '#FD919E',
        400: '#FC596E',
        500: '#FB223D',
        600: '#ed0421',
        700: '#C9031C',
        800: '#A10316',
        900: '#740714',
        950: '#48040D',
        DEFAULT: '#ed0421',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #FDF1F3,
  '100': #FCE4E7,
  '200': #FBC1C8,
  '300': #FD919E,
  '400': #FC596E,
  '500': #FB223D,
  '600': #ed0421,
  '700': #C9031C,
  '800': #A10316,
  '900': #740714,
  '950': #48040D,
);
$brand-base: #ed0421;
$brand-ink: #000000;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#FDF1F3", "$type": "color" },
      "100": { "$value": "#FCE4E7", "$type": "color" },
      "200": { "$value": "#FBC1C8", "$type": "color" },
      "300": { "$value": "#FD919E", "$type": "color" },
      "400": { "$value": "#FC596E", "$type": "color" },
      "500": { "$value": "#FB223D", "$type": "color" },
      "600": { "$value": "#ed0421", "$type": "color" },
      "700": { "$value": "#C9031C", "$type": "color" },
      "800": { "$value": "#A10316", "$type": "color" },
      "900": { "$value": "#740714", "$type": "color" },
      "950": { "$value": "#48040D", "$type": "color" }
    },
    "brandInk": { "$value": "#000000", "$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#000000 on #ed0421 · 4.64:1
Use #000000AA at every size, AAA for large text only.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 4.53:1
AA pass · AA large pass · AAA fail
Aa
Black text · 4.64:1 · recommended
AA pass · AA large pass · AAA fail
Reading the other direction: #ed0421 as text scores 4.53:1 on white and 4.64:1 on black.
Best tinted ink on it, if plain black or white feels flat: #7D0212 at 2.46:1.

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
#ed0421 · 4.53:1
AA on whitealready passes
#ed0421
The quick fox
#B10319 · 7.25:1
AAA on white−12% L
#B10319
The quick fox
#ed0421 · 4.64:1
AA on blackalready passes
#ed0421
The quick fox
#FC6074 · 7.06:1
AAA on black+21% L
#FC6074

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #ED0421 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
#ed0421 on white: 4.53:1
AA ✓ pass · AA-large · AAA
Aa
#ed0421 on black: 4.64:1
AA ✓ pass · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #ed0421 as text on that neutral, and that neutral as text on #ed0421.

NeutralRatioBoth directions
White4.53:1AaAa
Slate 504.33:1AaAa
Slate 1004.13:1AaAa
Slate 2003.67:1AaAa
Slate 3003.05:1AaAa
Slate 4001.77:1AaAa
Slate 5001.05:1AaAa
Slate 6001.67:1AaAa
Slate 7002.29:1AaAa
Slate 8003.23:1AaAa
Slate 9003.94:1AaAa
Black4.64:1AaAa
Colour vision deficiency
true color
protanopia · #64591E
deuteranopia · #97860F
tritanopia · #FF0019

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. #ed0421 is pinned to step 600; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#FDF1F3
#FCE4E7
#FBC1C8
#FD919E
#FC596E
#FB223D
#ed0421
#C9031C
#A10316
#740714
#48040D
Base = 600Lightest = 50 · #FDF1F3Darkest = 950 · #48040DText step on white = 600
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 0.060 26.2);
  --brand-100: oklch(0.94 0.097 26.2);
  --brand-200: oklch(0.88 0.145 26.2);
  --brand-300: oklch(0.80 0.188 26.2);
  --brand-400: oklch(0.72 0.222 26.2);
  --brand-500: oklch(0.64 0.241 26.2);
  --brand-600: oklch(0.56 0.241 26.2);
  --brand-700: oklch(0.48 0.227 26.2);
  --brand-800: oklch(0.40 0.203 26.2);
  --brand-900: oklch(0.32 0.169 26.2);
  --brand-950: oklch(0.24 0.133 26.2);
}

Colors that work with #ed0421

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

Text on it#000000
Black wins here
Surface#FAF4F5
Tinted page background
Border#EDC0C5
Hairlines and dividers
Muted text#9B4B55
Captions on the surface
Accent#00CC80
Second voice, not a rival
Dark variant#7D0212
Hover, pressed, headers
Light variant#FFE6E9
Selected rows, tints
Dark surface#241416
Dark-mode background
Hover#CA031C
One step down in lightness
Pressed#A70317
Two steps down
Disabled#C29FA4
Chroma pulled out
Focus ring#FF0726
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 #ed0421

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

Works well for
  • Body text and links on white
  • Text and icons on dark surfaces
  • 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
  • Status meaning — pair it with an icon or label, never colour alone
  • 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.

urgentappetisingboldphysical

Red arrives before the rest of the page does. It raises attention and appetite, which is why it runs food, sport and clearance pricing.

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 universal error colour. Use it as a brand accent and users may read a warning that is not there.

Reads as
  • FormalityLow
  • EnergyHigh
  • Weight53/100
  • TemperatureWarm
  • ApproachabilityHigh

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#04EDD0
Analogous left#ED0496
Analogous right#ED5B04
Split-complement 1#04ED5B
Split-complement 2#0496ED
Triadic 1#21ED04
Triadic 2#0421ED
Tetradic#96ED04
On the wheel
Base+30°−30°+120°+240°+180°353°

#ed0421 sits at 353°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red92.9%
Green1.6%
Blue12.9%
R · 0–255
237
0xed
G · 0–255
4
0x04
B · 0–255
33
0x21

CMYK percentages

Cyan0.0%
Magenta98.3%
Yellow86.1%
Key (black)7.1%

Total ink coverage is 191%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#ed0421 text on a black background

contrast 4.64:1

Card sample

#ed0421 text on a white background

contrast 4.53:1

Card sample

#ed0421 on grey

4.13:1

#ed0421 on its own surface

4.16:1

#ed0421 on its dark surface

3.91:1

CSS3 live lab

Text font color

The quick brown fox

color: #ed0421;
Background color
Panel with #ed0421 background
background-color: #ed0421;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #ed0421;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(237, 4, 33, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(237, 4, 33, 0.45);
Border & gradient
Gradient panel
border: 3px solid #ed0421;
background: linear-gradient(135deg, #ed0421, #ED8204);
Gradient text

Gradient headline

background: linear-gradient(90deg, #ed0421, #EDBD04);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #ed0421;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #ed0421;
caret-color: #ed0421;
Left rule
Pull quote or callout
border-left: 4px solid #ed0421;
Ring + tint
Selected chip
background: #FFE6E9;
box-shadow: inset 0 0 0 2px #ed0421;
Conic badge
68%
background: conic-gradient(#ed0421 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #ed0421 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(237, 4, 33, 0.5)
rgb(237 4 33 / 50%)
#ed042180
hsl(353 97% 47% / 50%)
color-mix(in srgb, #ed0421 50%, transparent)
Alpha8-digit hexFlat on white
10%#ed04211a#FDE6E9
20%#ed042133#FBCDD3
40%#ed042166#F89BA6
60%#ed042199#F4687A
80%#ed0421cc#F1364D

Gradients from #ed0421

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, #FC334C, #ed0421 45%, #7D0212);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #ed0421, #CF8303);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #ed0421, #04EDD0);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #FC5166 0%, #ed0421 45%, #7D0212 100%);
Soft wash
Section backgrounds that stay readable
background: linear-gradient(180deg, #FAF4F5, #ffffff);
Mesh
Ambient background, no image weight
background: radial-gradient(60% 60% at 15% 20%, #FB29BE 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #FB7E15 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #7D0212 0%, transparent 65%), #ed0421;

Monochromatic scale

Palettes built from #ed0421

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.

#ed0421 in the real world

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

Industries
Food and drinkEntertainmentRetailSport
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

Usable as-is on a dark surface at 4.64:1.

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.

#ed0421, answered

What color is #ed0421?

#ed0421 is a balanced electric red, closest to Red (ΔE2000 6.1). It sits at 353° on the hue wheel with 97% saturation and 47% lightness, which reads as warm.

What is the RGB value of #ed0421?

rgb(237, 4, 33) — 237 red, 4 green and 33 blue out of 255, or 92.9% / 1.6% / 12.9% by channel.

What is #ed0421 in HSL and HSV?

hsl(353, 97%, 47%) and hsv(353, 98%, 93%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #ed0421 a light or a dark color?

It is a mid-tone. Relative luminance is 0.1820 and perceived brightness is 51%, so black text on it reaches 4.64:1.

Should I use black or white text on #ed0421?

Black. It scores 4.64:1 against #ed0421, versus 4.53:1 for white — AA at any size.

Is #ed0421 accessible on a white background?

#ed0421 on white scores 4.53:1, which clears AA at every size but not AAA.

What is the complementary color of #ed0421?

#04EDD0 sits directly opposite on the wheel. Softer options are the split-complements #04ED5B and #0496ED, which give the same contrast with far less vibration.

What colors go well with #ed0421?

For interface work: #FAF4F5 as the surface, #EDC0C5 for borders, #9B4B55 for secondary text, #00CC80 as an accent and #7D0212 for hover and pressed states. For a palette, the analogous pair #ED0496 and #ED5B04 stays calm, while #04EDD0 is the loudest partner.

What is #ed0421 in CMYK for printing?

cmyk(0%, 98%, 86%, 7%). 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 #ed0421 warm or cool?

Warm — it scores 21 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #ED2904; nudged cooler, #F00277.

Which Tailwind color is closest to #ed0421?

The red family — its 500 step is #ef4444, ΔE2000 6.7 away. That is a visible difference, so define #ed0421 as a custom token rather than reaching for the built-in.

How do I use #ed0421 in Tailwind CSS?

Inline it as an arbitrary value with bg-[#ed0421] or text-[#ed0421], 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 #ed0421 with 50% opacity?

rgba(237, 4, 33, 0.5), or #ed042180 in eight-digit hex. Over white that composites to #F68290; over black, #770211.

Is #ed0421 a web-safe color?

No. The nearest web-safe colour is #FF0033, ΔE2000 4.8 away. The palette only matters for legacy displays and some email clients now.

What does the color #ed0421 mean?

As a red, it reads urgent, appetising, bold. Red arrives before the rest of the page does. It raises attention and appetite, which is why it runs food, sport and clearance pricing. At this chroma the effect is amplified — it will dominate whatever sits beside it.

What gradient works with #ed0421?

The safest is same-hue elevation: linear-gradient(135deg, #FC334C, #ed0421 45%, #7D0212). For more colour, a short hue run to #CF8303 keeps it rich without turning muddy.

Work with #ed0421 in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #ed0421 at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.