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red · warm

#a31921

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

Token name suggestion: Shadow Cardinal

RGB
163, 25, 33
HSL
357°, 73%, 37%
CMYK
0, 85, 80, 36
Luminance
0.0859

#a31921 is a dark vivid red, 357° on the wheel and 19/100 on the cool side. Put white text on it (7.73:1). As text it scores 7.73:1 on white — safe at any size. Nearest name is Brown, nearest Tailwind family is red.

hsl(357 73% 37%)rgb(163 25 33)Base step 700AAA inkWarm

At a glance

Every number on this page in one read: what #a31921 is made of, how bright it looks, and which way it leans.

Hex
#a31921
Hue
357°
red
Saturation
73%
vivid
Lightness
37%
dark
Brightness
64%
HSV value
Perceived
36%
weighted brightness
Luminance
0.0859
WCAG relative
Temperature
Warm
19/100 cool
Color family
Red
Tone
Vivid
Best ink
White
7.73:1
Closest name
Brown
ΔE2000 2.4
Chroma
63.3
LCH, 0–130ish
OKLCH L
0.462
perceptual lightness
Tailwind
red
500 · ΔE 19
Web-safe
#990033
nearest of 216
Where it sits
Hue357° of 360°
Saturation73%
Lightness37%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #a31921.

Temperature
Warm ← → Cool19% 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
Red91%
Green8%
Blue1%

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

Every format

HEX#a31921
HEX (8-digit)#a31921ff
RGBrgb(163, 25, 33)
RGBArgba(163, 25, 33, 1)
HSLhsl(357, 73%, 37%)
HSV / HSBhsv(357, 85%, 64%)
HWBhwb(357 10% 36%)
CMYKcmyk(0%, 85%, 80%, 36%)
LABlab(35.2 53.9 33.2)
LCHlch(35.2 63.3 31.7)
OKLCHoklch(0.462 0.172 25.0)
XYZ (D65)xyz(15.73, 8.59, 2.27)
Decimal10688801
Display P3color(display-p3 0.639 0.098 0.129)
Web-safe#990033

Copy-ready code

every platformclick to select
/* CSS */
color: #a31921;
background-color: #a31921;
/* CSS custom property */
--brand: #a31921;
/* Tailwind (arbitrary) */
class="text-[#a31921] bg-[#a31921]"
/* SCSS */
$brand: #a31921;
/* SwiftUI */
Color(red: 0.639, green: 0.098, blue: 0.129)
/* UIKit */
UIColor(red: 0.639, green: 0.098, blue: 0.129, alpha: 1)
/* Android XML */
<color name="brand">#A31921</color>
/* Android Compose */
Color(0xFFA31921)
/* Flutter */
Color(0xFFA31921)
/* Python / OpenCV (BGR) */
(33, 25, 163)
/* Python / PIL (RGB) */
(163, 25, 33)
/* Java AWT */
new Color(163, 25, 33)
/* .NET */
Color.FromArgb(255, 163, 25, 33)
/* OpenGL / Unity (0–1) */
(0.6392f, 0.0980f, 0.1294f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{163,25,33}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #a31921 85%, white);
border-color: color-mix(in oklab, #a31921 40%, transparent);
/* theme-aware in one line */
color: light-dark(#6F1116, #EED3D4);
/* relative colour syntax */
--hover: hsl(from #a31921 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: #FCF3F3;
  --brand-100: #F8E7E8;
  --brand-200: #F3C8CB;
  --brand-300: #F09EA3;
  --brand-400: #E96D74;
  --brand-500: #E13C46;
  --brand-600: #D4212B;
  --brand-700: #a31921;
  --brand-800: #8D161D;
  --brand-900: #671419;
  --brand-950: #400C0F;
  --brand: #a31921;
  --brand-ink: #ffffff;
  --brand-surface: #FAF4F5;
  --brand-border: #EDC0C2;
  --brand-hover: #84141B;
  --brand-pressed: #651015;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #241415;
    --brand-ink: #EED3D4;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#FCF3F3',
        100: '#F8E7E8',
        200: '#F3C8CB',
        300: '#F09EA3',
        400: '#E96D74',
        500: '#E13C46',
        600: '#D4212B',
        700: '#a31921',
        800: '#8D161D',
        900: '#671419',
        950: '#400C0F',
        DEFAULT: '#a31921',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #FCF3F3,
  '100': #F8E7E8,
  '200': #F3C8CB,
  '300': #F09EA3,
  '400': #E96D74,
  '500': #E13C46,
  '600': #D4212B,
  '700': #a31921,
  '800': #8D161D,
  '900': #671419,
  '950': #400C0F,
);
$brand-base: #a31921;
$brand-ink: #ffffff;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#FCF3F3", "$type": "color" },
      "100": { "$value": "#F8E7E8", "$type": "color" },
      "200": { "$value": "#F3C8CB", "$type": "color" },
      "300": { "$value": "#F09EA3", "$type": "color" },
      "400": { "$value": "#E96D74", "$type": "color" },
      "500": { "$value": "#E13C46", "$type": "color" },
      "600": { "$value": "#D4212B", "$type": "color" },
      "700": { "$value": "#a31921", "$type": "color" },
      "800": { "$value": "#8D161D", "$type": "color" },
      "900": { "$value": "#671419", "$type": "color" },
      "950": { "$value": "#400C0F", "$type": "color" }
    },
    "brandInk": { "$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 #a31921 · 7.73:1
Use #ffffffAAA at every size.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 7.73:1 · recommended
AA pass · AA large pass · AAA pass
Aa
Black text · 2.72:1
AA fail · AA large fail · AAA fail
Reading the other direction: #a31921 as text scores 7.73:1 on white and 2.72:1 on black.
Best tinted ink on it, if plain black or white feels flat: #FCE9EA at 6.62:1.

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
#a31921 · 7.73:1
AA on whitealready passes
#a31921
The quick fox
#a31921 · 7.73:1
AAA on whitealready passes
#a31921
The quick fox
#DF2F39 · 4.60:1
AA on black+16% L
#DF2F39
The quick fox
#E97178 · 7.10:1
AAA on black+31% L
#E97178

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #A31921 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
#a31921 on white: 7.73:1
AA ✓ pass · AA-large · AAA
Aa
#a31921 on black: 2.72:1
AA ✗ fail · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #a31921 as text on that neutral, and that neutral as text on #a31921.

NeutralRatioBoth directions
White7.73:1AaAa
Slate 507.38:1AaAa
Slate 1007.05:1AaAa
Slate 2006.27:1AaAa
Slate 3005.20:1AaAa
Slate 4003.01:1AaAa
Slate 5001.62:1AaAa
Slate 6001.02:1AaAa
Slate 7001.34:1AaAa
Slate 8001.89:1AaAa
Slate 9002.31:1AaAa
Black2.72:1AaAa
Colour vision deficiency
true color
protanopia · #474020
deuteranopia · #685D1B
tritanopia · #B4001E

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. #a31921 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.

#FCF3F3
#F8E7E8
#F3C8CB
#F09EA3
#E96D74
#E13C46
#D4212B
#a31921
#8D161D
#671419
#400C0F
Base = 700Lightest = 50 · #FCF3F3Darkest = 950 · #400C0FText 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 0.043 25.0);
  --brand-100: oklch(0.94 0.069 25.0);
  --brand-200: oklch(0.88 0.103 25.0);
  --brand-300: oklch(0.80 0.134 25.0);
  --brand-400: oklch(0.72 0.158 25.0);
  --brand-500: oklch(0.64 0.172 25.0);
  --brand-600: oklch(0.56 0.172 25.0);
  --brand-700: oklch(0.48 0.161 25.0);
  --brand-800: oklch(0.40 0.144 25.0);
  --brand-900: oklch(0.32 0.120 25.0);
  --brand-950: oklch(0.24 0.094 25.0);
}

Colors that work with #a31921

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#FAF4F5
Tinted page background
Border#EDC0C2
Hairlines and dividers
Muted text#9B4B4F
Captions on the surface
Accent#17B584
Second voice, not a rival
Dark variant#6F1116
Hover, pressed, headers
Light variant#FCE9EA
Selected rows, tints
Dark surface#241415
Dark-mode background
Hover#84141B
One step down in lightness
Pressed#651015
Two steps down
Disabled#AD7F82
Chroma pulled out
Focus ring#BF111B
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 #a31921

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
  • Text on black or near-black surfaces
  • 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
  • Weight63/100
  • 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#19A39B
Analogous left#A31966
Analogous right#A35619
Split-complement 1#19A356
Split-complement 2#1966A3
Triadic 1#21A319
Triadic 2#1921A3
Tetradic#66A319
On the wheel
Base+30°−30°+120°+240°+180°357°

#a31921 sits at 357°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red63.9%
Green9.8%
Blue12.9%
R · 0–255
163
0xa3
G · 0–255
25
0x19
B · 0–255
33
0x21

CMYK percentages

Cyan0.0%
Magenta84.7%
Yellow79.8%
Key (black)36.1%

Total ink coverage is 201%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#a31921 text on a black background

contrast 2.72:1

Card sample

#a31921 text on a white background

contrast 7.73:1

Card sample

#a31921 on grey

7.05:1

#a31921 on its own surface

7.11:1

#a31921 on its dark surface

2.29:1

CSS3 live lab

Text font color

The quick brown fox

color: #a31921;
Background color
Panel with #a31921 background
background-color: #a31921;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #a31921;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(163, 25, 33, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(163, 25, 33, 0.45);
Border & gradient
Gradient panel
border: 3px solid #a31921;
background: linear-gradient(135deg, #a31921, #A36D19);
Gradient text

Gradient headline

background: linear-gradient(90deg, #a31921, #A39019);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #a31921;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #a31921;
caret-color: #a31921;
Left rule
Pull quote or callout
border-left: 4px solid #a31921;
Ring + tint
Selected chip
background: #FCE9EA;
box-shadow: inset 0 0 0 2px #a31921;
Conic badge
68%
background: conic-gradient(#a31921 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #a31921 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(163, 25, 33, 0.5)
rgb(163 25 33 / 50%)
#a3192180
hsl(357 73% 37% / 50%)
color-mix(in srgb, #a31921 50%, transparent)
Alpha8-digit hexFlat on white
10%#a319211a#F6E8E9
20%#a3192133#EDD1D3
40%#a3192166#DAA3A6
60%#a3192199#C8757A
80%#a31921cc#B5474D

Gradients from #a31921

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, #D8212C, #a31921 45%, #6F1116);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #a31921, #896515);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #a31921, #19A39B);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #E03841 0%, #a31921 45%, #6F1116 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%, #CF2090 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #BE711D 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #6F1116 0%, transparent 65%), #a31921;

Monochromatic scale

Palettes built from #a31921

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.

#a31921 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 2.72:1 — lift it to #DF2F39 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.

#a31921, answered

What color is #a31921?

#a31921 is a dark vivid red, closest to Brown (ΔE2000 2.4). It sits at 357° on the hue wheel with 73% saturation and 37% lightness, which reads as warm.

What is the RGB value of #a31921?

rgb(163, 25, 33) — 163 red, 25 green and 33 blue out of 255, or 63.9% / 9.8% / 12.9% by channel.

What is #a31921 in HSL and HSV?

hsl(357, 73%, 37%) and hsv(357, 85%, 64%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #a31921 a light or a dark color?

It is a dark color. Relative luminance is 0.0859 and perceived brightness is 36%, so white text on it reaches 7.73:1.

Should I use black or white text on #a31921?

White. It scores 7.73:1 against #a31921, versus 2.72:1 for black — AAA at any size.

Is #a31921 accessible on a white background?

#a31921 on white scores 7.73:1, which clears AAA at every size.

What is the complementary color of #a31921?

#19A39B sits directly opposite on the wheel. Softer options are the split-complements #19A356 and #1966A3, which give the same contrast with far less vibration.

What colors go well with #a31921?

For interface work: #FAF4F5 as the surface, #EDC0C2 for borders, #9B4B4F for secondary text, #17B584 as an accent and #6F1116 for hover and pressed states. For a palette, the analogous pair #A31966 and #A35619 stays calm, while #19A39B is the loudest partner.

What is #a31921 in CMYK for printing?

cmyk(0%, 85%, 80%, 36%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #a31921 warm or cool?

Warm — it scores 19 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #A33C19; nudged cooler, #A51753.

Which Tailwind color is closest to #a31921?

The red family — its 500 step is #ef4444, ΔE2000 19 away. That is a visible difference, so define #a31921 as a custom token rather than reaching for the built-in.

How do I use #a31921 in Tailwind CSS?

Inline it as an arbitrary value with bg-[#a31921] or text-[#a31921], 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 #a31921 with 50% opacity?

rgba(163, 25, 33, 0.5), or #a3192180 in eight-digit hex. Over white that composites to #D18C90; over black, #520D11.

Is #a31921 a web-safe color?

No. The nearest web-safe colour is #990033, ΔE2000 9 away. The palette only matters for legacy displays and some email clients now.

What does the color #a31921 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 #a31921?

The safest is same-hue elevation: linear-gradient(135deg, #D8212C, #a31921 45%, #6F1116). For more colour, a short hue run to #896515 keeps it rich without turning muddy.

Work with #a31921 in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #a31921 at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.