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red · warm

#ac2821

a dark, vivid red · warm · closest name: Firebrick

Token name suggestion: Shadow Ember

RGB
172, 40, 33
HSL
3°, 68%, 40%
CMYK
0, 77, 81, 33
Luminance
0.1040

#ac2821 is a dark vivid red, 3° on the wheel and 15/100 on the cool side. Put white text on it (6.82:1). As text it scores 6.82:1 on white — safe at any size. Nearest name is Firebrick, nearest Tailwind family is red.

hsl(3 68% 40%)rgb(172 40 33)Base step 700AA inkWarm

At a glance

Every number on this page in one read: what #ac2821 is made of, how bright it looks, and which way it leans.

Hex
#ac2821
Hue
red
Saturation
68%
vivid
Lightness
40%
dark
Brightness
67%
HSV value
Perceived
39%
weighted brightness
Luminance
0.1040
WCAG relative
Temperature
Warm
15/100 cool
Color family
Red
Tone
Vivid
Best ink
White
6.82:1
Closest name
Firebrick
ΔE2000 1.4
Chroma
64.2
LCH, 0–130ish
OKLCH L
0.490
perceptual lightness
Tailwind
red
500 · ΔE 16.5
Web-safe
#993333
nearest of 216
Where it sits
Hue3° of 360°
Saturation68%
Lightness40%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #ac2821.

Temperature
Warm ← → Cool15% 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
Red84%
Green15%
Blue1%

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

Every format

HEX#ac2821
HEX (8-digit)#ac2821ff
RGBrgb(172, 40, 33)
RGBArgba(172, 40, 33, 1)
HSLhsl(3, 68%, 40%)
HSV / HSBhsv(3, 81%, 67%)
HWBhwb(3 13% 33%)
CMYKcmyk(0%, 77%, 81%, 33%)
LABlab(38.5 52.3 37.2)
LCHlch(38.5 64.2 35.5)
OKLCHoklch(0.490 0.170 28.3)
XYZ (D65)xyz(18.05, 10.40, 2.50)
Decimal11282465
Display P3color(display-p3 0.675 0.157 0.129)
Web-safe#993333

Copy-ready code

every platformclick to select
/* CSS */
color: #ac2821;
background-color: #ac2821;
/* CSS custom property */
--brand: #ac2821;
/* Tailwind (arbitrary) */
class="text-[#ac2821] bg-[#ac2821]"
/* SCSS */
$brand: #ac2821;
/* SwiftUI */
Color(red: 0.675, green: 0.157, blue: 0.129)
/* UIKit */
UIColor(red: 0.675, green: 0.157, blue: 0.129, alpha: 1)
/* Android XML */
<color name="brand">#AC2821</color>
/* Android Compose */
Color(0xFFAC2821)
/* Flutter */
Color(0xFFAC2821)
/* Python / OpenCV (BGR) */
(33, 40, 172)
/* Python / PIL (RGB) */
(172, 40, 33)
/* Java AWT */
new Color(172, 40, 33)
/* .NET */
Color.FromArgb(255, 172, 40, 33)
/* OpenGL / Unity (0–1) */
(0.6745f, 0.1569f, 0.1294f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{172,40,33}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #ac2821 85%, white);
border-color: color-mix(in oklab, #ac2821 40%, transparent);
/* theme-aware in one line */
color: light-dark(#6B1915, #EED4D3);
/* relative colour syntax */
--hover: hsl(from #ac2821 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: #FBF4F3;
  --brand-100: #F8E8E8;
  --brand-200: #F2CCCA;
  --brand-300: #EDA5A1;
  --brand-400: #E47872;
  --brand-500: #DB4A43;
  --brand-600: #CD3027;
  --brand-700: #ac2821;
  --brand-800: #89201A;
  --brand-900: #631B17;
  --brand-950: #3E110E;
  --brand: #ac2821;
  --brand-ink: #ffffff;
  --brand-surface: #FAF5F4;
  --brand-border: #EDC2C0;
  --brand-hover: #8E211B;
  --brand-pressed: #701A16;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #241414;
    --brand-ink: #EED4D3;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#FBF4F3',
        100: '#F8E8E8',
        200: '#F2CCCA',
        300: '#EDA5A1',
        400: '#E47872',
        500: '#DB4A43',
        600: '#CD3027',
        700: '#ac2821',
        800: '#89201A',
        900: '#631B17',
        950: '#3E110E',
        DEFAULT: '#ac2821',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #FBF4F3,
  '100': #F8E8E8,
  '200': #F2CCCA,
  '300': #EDA5A1,
  '400': #E47872,
  '500': #DB4A43,
  '600': #CD3027,
  '700': #ac2821,
  '800': #89201A,
  '900': #631B17,
  '950': #3E110E,
);
$brand-base: #ac2821;
$brand-ink: #ffffff;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#FBF4F3", "$type": "color" },
      "100": { "$value": "#F8E8E8", "$type": "color" },
      "200": { "$value": "#F2CCCA", "$type": "color" },
      "300": { "$value": "#EDA5A1", "$type": "color" },
      "400": { "$value": "#E47872", "$type": "color" },
      "500": { "$value": "#DB4A43", "$type": "color" },
      "600": { "$value": "#CD3027", "$type": "color" },
      "700": { "$value": "#ac2821", "$type": "color" },
      "800": { "$value": "#89201A", "$type": "color" },
      "900": { "$value": "#631B17", "$type": "color" },
      "950": { "$value": "#3E110E", "$type": "color" }
    },
    "brandInk": { "$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 #ac2821 · 6.82:1
Use #ffffffAA at every size, AAA for large text only.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 6.82:1 · recommended
AA pass · AA large pass · AAA fail
Aa
Black text · 3.08:1
AA fail · AA large pass · AAA fail
Reading the other direction: #ac2821 as text scores 6.82:1 on white and 3.08:1 on black.
Best tinted ink on it, if plain black or white feels flat: #FBEAEA at 5.86:1.

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
#ac2821 · 6.82:1
AA on whitealready passes
#ac2821
The quick fox
#A82720 · 7.06:1
AAA on white−1% L
#A82720
The quick fox
#D83B32 · 4.59:1
AA on black+12% L
#D83B32
The quick fox
#E47873 · 7.23:1
AAA on black+27% L
#E47873

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #AC2821 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
#ac2821 on white: 6.82:1
AA ✓ pass · AA-large · AAA
Aa
#ac2821 on black: 3.08:1
AA ✗ fail · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #ac2821 as text on that neutral, and that neutral as text on #ac2821.

NeutralRatioBoth directions
White6.82:1AaAa
Slate 506.52:1AaAa
Slate 1006.22:1AaAa
Slate 2005.53:1AaAa
Slate 3004.59:1AaAa
Slate 4002.66:1AaAa
Slate 5001.43:1AaAa
Slate 6001.11:1AaAa
Slate 7001.52:1AaAa
Slate 8002.15:1AaAa
Slate 9002.62:1AaAa
Black3.08:1AaAa
Colour vision deficiency
true color
protanopia · #51481F
deuteranopia · #71651B
tritanopia · #BE0028

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. #ac2821 is pinned to step 700; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#FBF4F3
#F8E8E8
#F2CCCA
#EDA5A1
#E47872
#DB4A43
#CD3027
#ac2821
#89201A
#631B17
#3E110E
Base = 700Lightest = 50 · #FBF4F3Darkest = 950 · #3E110EText 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 0.042 28.3);
  --brand-100: oklch(0.94 0.068 28.3);
  --brand-200: oklch(0.88 0.102 28.3);
  --brand-300: oklch(0.80 0.132 28.3);
  --brand-400: oklch(0.72 0.156 28.3);
  --brand-500: oklch(0.64 0.170 28.3);
  --brand-600: oklch(0.56 0.170 28.3);
  --brand-700: oklch(0.48 0.159 28.3);
  --brand-800: oklch(0.40 0.142 28.3);
  --brand-900: oklch(0.32 0.119 28.3);
  --brand-950: oklch(0.24 0.093 28.3);
}

Colors that work with #ac2821

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#FAF5F4
Tinted page background
Border#EDC2C0
Hairlines and dividers
Muted text#9B4F4B
Captions on the surface
Accent#1DAF92
Second voice, not a rival
Dark variant#6B1915
Hover, pressed, headers
Light variant#FBEAEA
Selected rows, tints
Dark surface#241414
Dark-mode background
Hover#8E211B
One step down in lightness
Pressed#701A16
Two steps down
Disabled#B48C89
Chroma pulled out
Focus ring#C82219
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 #ac2821

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
  • Headers, footers and dark-mode surfaces
  • Brand accents, badges and data highlights
Use with care
  • Full-page backgrounds — tiring over long sessions
  • Black text placed on it
  • 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.

This is a confident chroma: strong enough to lead a brand, restrained enough to live in an interface all day. The low lightness adds weight and formality.

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
  • FormalityHigh
  • EnergyMedium-high
  • Weight60/100
  • 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#21A5AC
Analogous left#AC2160
Analogous right#AC6D21
Split-complement 1#21AC6D
Split-complement 2#2160AC
Triadic 1#21AC28
Triadic 2#2821AC
Tetradic#60AC21
On the wheel
Base+30°−30°+120°+240°+180°3°

#ac2821 sits at 3°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red67.5%
Green15.7%
Blue12.9%
R · 0–255
172
0xac
G · 0–255
40
0x28
B · 0–255
33
0x21

CMYK percentages

Cyan0.0%
Magenta76.7%
Yellow80.8%
Key (black)32.5%

Total ink coverage is 190%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#ac2821 text on a black background

contrast 3.08:1

Card sample

#ac2821 text on a white background

contrast 6.82:1

Card sample

#ac2821 on grey

6.22:1

#ac2821 on its own surface

6.31:1

#ac2821 on its dark surface

2.60:1

CSS3 live lab

Text font color

The quick brown fox

color: #ac2821;
Background color
Panel with #ac2821 background
background-color: #ac2821;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #ac2821;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(172, 40, 33, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(172, 40, 33, 0.45);
Border & gradient
Gradient panel
border: 3px solid #ac2821;
background: linear-gradient(135deg, #ac2821, #AC8521);
Gradient text

Gradient headline

background: linear-gradient(90deg, #ac2821, #ACA721);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #ac2821;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #ac2821;
caret-color: #ac2821;
Left rule
Pull quote or callout
border-left: 4px solid #ac2821;
Ring + tint
Selected chip
background: #FBEAEA;
box-shadow: inset 0 0 0 2px #ac2821;
Conic badge
68%
background: conic-gradient(#ac2821 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #ac2821 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(172, 40, 33, 0.5)
rgb(172 40 33 / 50%)
#ac282180
hsl(3 68% 40% / 50%)
color-mix(in srgb, #ac2821 50%, transparent)
Alpha8-digit hexFlat on white
10%#ac28211a#F7EAE9
20%#ac282133#EED4D3
40%#ac282166#DEA9A6
60%#ac282199#CD7E7A
80%#ac2821cc#BD534D

Gradients from #ac2821

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, #D83B32, #ac2821 45%, #6B1915);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #ac2821, #927B1C);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #ac2821, #21A5AC);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #DD534C 0%, #ac2821 45%, #6B1915 100%);
Soft wash
Section backgrounds that stay readable
background: linear-gradient(180deg, #FAF5F4, #ffffff);
Mesh
Ambient background, no image weight
background: radial-gradient(60% 60% at 15% 20%, #D62A86 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #C68B26 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #6B1915 0%, transparent 65%), #ac2821;

Monochromatic scale

Palettes built from #ac2821

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.

#ac2821 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

Converts to four-color process without much drama. Proof it anyway.

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 3.08:1 — lift it to #D83B32 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.

#ac2821, answered

What color is #ac2821?

#ac2821 is a dark vivid red, closest to Firebrick (ΔE2000 1.4). It sits at 3° on the hue wheel with 68% saturation and 40% lightness, which reads as warm.

What is the RGB value of #ac2821?

rgb(172, 40, 33) — 172 red, 40 green and 33 blue out of 255, or 67.5% / 15.7% / 12.9% by channel.

What is #ac2821 in HSL and HSV?

hsl(3, 68%, 40%) and hsv(3, 81%, 67%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #ac2821 a light or a dark color?

It is a dark color. Relative luminance is 0.1040 and perceived brightness is 39%, so white text on it reaches 6.82:1.

Should I use black or white text on #ac2821?

White. It scores 6.82:1 against #ac2821, versus 3.08:1 for black — AA at any size.

Is #ac2821 accessible on a white background?

#ac2821 on white scores 6.82:1, which clears AA at every size but not AAA.

What is the complementary color of #ac2821?

#21A5AC sits directly opposite on the wheel. Softer options are the split-complements #21AC6D and #2160AC, which give the same contrast with far less vibration.

What colors go well with #ac2821?

For interface work: #FAF5F4 as the surface, #EDC2C0 for borders, #9B4F4B for secondary text, #1DAF92 as an accent and #6B1915 for hover and pressed states. For a palette, the analogous pair #AC2160 and #AC6D21 stays calm, while #21A5AC is the loudest partner.

What is #ac2821 in CMYK for printing?

cmyk(0%, 77%, 81%, 33%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #ac2821 warm or cool?

Warm — it scores 15 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #AC4821; nudged cooler, #AE1F4C.

Which Tailwind color is closest to #ac2821?

The red family — its 500 step is #ef4444, ΔE2000 16.5 away. That is a visible difference, so define #ac2821 as a custom token rather than reaching for the built-in.

How do I use #ac2821 in Tailwind CSS?

Inline it as an arbitrary value with bg-[#ac2821] or text-[#ac2821], 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 #ac2821 with 50% opacity?

rgba(172, 40, 33, 0.5), or #ac282180 in eight-digit hex. Over white that composites to #D69490; over black, #561411.

Is #ac2821 a web-safe color?

No. The nearest web-safe colour is #993333, ΔE2000 6 away. The palette only matters for legacy displays and some email clients now.

What does the color #ac2821 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 #ac2821?

The safest is same-hue elevation: linear-gradient(135deg, #D83B32, #ac2821 45%, #6B1915). For more colour, a short hue run to #927B1C keeps it rich without turning muddy.

Work with #ac2821 in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #ac2821 at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.