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red · warm

#ac050f

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

Token name suggestion: Slate Cardinal

RGB
172, 5, 15
HSL
356°, 94%, 35%
CMYK
0, 97, 91, 33
Luminance
0.0891

#ac050f is a dark electric red, 356° on the wheel and 19/100 on the cool side. Put white text on it (7.55:1). As text it scores 7.55:1 on white — safe at any size. Nearest name is Firebrick, nearest Tailwind family is red.

hsl(356 94% 35%)rgb(172 5 15)Base step 800AAA inkWarm

At a glance

Every number on this page in one read: what #ac050f is made of, how bright it looks, and which way it leans.

Hex
#ac050f
Hue
356°
red
Saturation
94%
electric
Lightness
35%
dark
Brightness
67%
HSV value
Perceived
37%
weighted brightness
Luminance
0.0891
WCAG relative
Temperature
Warm
19/100 cool
Color family
Red
Tone
Electric
Best ink
White
7.55:1
Closest name
Firebrick
ΔE2000 3.7
Chroma
73.8
LCH, 0–130ish
OKLCH L
0.470
perceptual lightness
Tailwind
red
500 · ΔE 18.7
Web-safe
#990000
nearest of 216
Where it sits
Hue356° of 360°
Saturation94%
Lightness35%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #ac050f.

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
Red98%
Green1%
Blue0%

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

Every format

HEX#ac050f
HEX (8-digit)#ac050fff
RGBrgb(172, 5, 15)
RGBArgba(172, 5, 15, 1)
HSLhsl(356, 94%, 35%)
HSV / HSBhsv(356, 97%, 67%)
HWBhwb(356 2% 33%)
CMYKcmyk(0%, 97%, 91%, 33%)
LABlab(35.8 59.2 44.0)
LCHlch(35.8 73.8 36.6)
OKLCHoklch(0.470 0.189 27.5)
XYZ (D65)xyz(17.16, 8.92, 1.27)
Decimal11273487
Display P3color(display-p3 0.675 0.020 0.059)
Web-safe#990000

Copy-ready code

every platformclick to select
/* CSS */
color: #ac050f;
background-color: #ac050f;
/* CSS custom property */
--brand: #ac050f;
/* Tailwind (arbitrary) */
class="text-[#ac050f] bg-[#ac050f]"
/* SCSS */
$brand: #ac050f;
/* SwiftUI */
Color(red: 0.675, green: 0.020, blue: 0.059)
/* UIKit */
UIColor(red: 0.675, green: 0.020, blue: 0.059, alpha: 1)
/* Android XML */
<color name="brand">#AC050F</color>
/* Android Compose */
Color(0xFFAC050F)
/* Flutter */
Color(0xFFAC050F)
/* Python / OpenCV (BGR) */
(15, 5, 172)
/* Python / PIL (RGB) */
(172, 5, 15)
/* Java AWT */
new Color(172, 5, 15)
/* .NET */
Color.FromArgb(255, 172, 5, 15)
/* OpenGL / Unity (0–1) */
(0.6745f, 0.0196f, 0.0588f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{172,5,15}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #ac050f 85%, white);
border-color: color-mix(in oklab, #ac050f 40%, transparent);
/* theme-aware in one line */
color: light-dark(#7C040B, #EED3D4);
/* relative colour syntax */
--hover: hsl(from #ac050f 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: #FDF2F2;
  --brand-100: #FBE4E5;
  --brand-200: #FAC2C5;
  --brand-300: #FC9298;
  --brand-400: #FA5B65;
  --brand-500: #F92532;
  --brand-600: #EE0715;
  --brand-700: #C60611;
  --brand-800: #ac050f;
  --brand-900: #72080E;
  --brand-950: #470509;
  --brand: #ac050f;
  --brand-ink: #ffffff;
  --brand-surface: #FAF4F5;
  --brand-border: #EDC0C2;
  --brand-hover: #89040C;
  --brand-pressed: #670309;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #241415;
    --brand-ink: #EED3D4;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#FDF2F2',
        100: '#FBE4E5',
        200: '#FAC2C5',
        300: '#FC9298',
        400: '#FA5B65',
        500: '#F92532',
        600: '#EE0715',
        700: '#C60611',
        800: '#ac050f',
        900: '#72080E',
        950: '#470509',
        DEFAULT: '#ac050f',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #FDF2F2,
  '100': #FBE4E5,
  '200': #FAC2C5,
  '300': #FC9298,
  '400': #FA5B65,
  '500': #F92532,
  '600': #EE0715,
  '700': #C60611,
  '800': #ac050f,
  '900': #72080E,
  '950': #470509,
);
$brand-base: #ac050f;
$brand-ink: #ffffff;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#FDF2F2", "$type": "color" },
      "100": { "$value": "#FBE4E5", "$type": "color" },
      "200": { "$value": "#FAC2C5", "$type": "color" },
      "300": { "$value": "#FC9298", "$type": "color" },
      "400": { "$value": "#FA5B65", "$type": "color" },
      "500": { "$value": "#F92532", "$type": "color" },
      "600": { "$value": "#EE0715", "$type": "color" },
      "700": { "$value": "#C60611", "$type": "color" },
      "800": { "$value": "#ac050f", "$type": "color" },
      "900": { "$value": "#72080E", "$type": "color" },
      "950": { "$value": "#470509", "$type": "color" }
    },
    "brandInk": { "$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 #ac050f · 7.55:1
Use #ffffffAAA at every size.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 7.55:1 · recommended
AA pass · AA large pass · AAA pass
Aa
Black text · 2.78:1
AA fail · AA large fail · AAA fail
Reading the other direction: #ac050f as text scores 7.55:1 on white and 2.78:1 on black.
Best tinted ink on it, if plain black or white feels flat: #FEE6E8 at 6.36:1.

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
#ac050f · 7.55:1
AA on whitealready passes
#ac050f
The quick fox
#ac050f · 7.55:1
AAA on whitealready passes
#ac050f
The quick fox
#EC0715 · 4.61:1
AA on black+13% L
#EC0715
The quick fox
#FB646D · 7.15:1
AAA on black+34% L
#FB646D

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #AC050F 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
#ac050f on white: 7.55:1
AA ✓ pass · AA-large · AAA
Aa
#ac050f on black: 2.78:1
AA ✗ fail · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #ac050f as text on that neutral, and that neutral as text on #ac050f.

NeutralRatioBoth directions
White7.55:1AaAa
Slate 507.21:1AaAa
Slate 1006.89:1AaAa
Slate 2006.12:1AaAa
Slate 3005.08:1AaAa
Slate 4002.94:1AaAa
Slate 5001.59:1AaAa
Slate 6001.00:1AaAa
Slate 7001.37:1AaAa
Slate 8001.94:1AaAa
Slate 9002.37:1AaAa
Black2.78:1AaAa
Colour vision deficiency
true color
protanopia · #473E0B
deuteranopia · #6D6000
tritanopia · #BE000E

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. #ac050f is pinned to step 800; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#FDF2F2
#FBE4E5
#FAC2C5
#FC9298
#FA5B65
#F92532
#EE0715
#C60611
#ac050f
#72080E
#470509
Base = 800Lightest = 50 · #FDF2F2Darkest = 950 · #470509Text step on white = 700
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 0.047 27.5);
  --brand-100: oklch(0.94 0.076 27.5);
  --brand-200: oklch(0.88 0.114 27.5);
  --brand-300: oklch(0.80 0.148 27.5);
  --brand-400: oklch(0.72 0.174 27.5);
  --brand-500: oklch(0.64 0.189 27.5);
  --brand-600: oklch(0.56 0.189 27.5);
  --brand-700: oklch(0.48 0.178 27.5);
  --brand-800: oklch(0.40 0.159 27.5);
  --brand-900: oklch(0.32 0.133 27.5);
  --brand-950: oklch(0.24 0.104 27.5);
}

Colors that work with #ac050f

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#01CB8D
Second voice, not a rival
Dark variant#7C040B
Hover, pressed, headers
Light variant#FEE6E8
Selected rows, tints
Dark surface#241415
Dark-mode background
Hover#89040C
One step down in lightness
Pressed#670309
Two steps down
Disabled#A9787B
Chroma pulled out
Focus ring#C5000C
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 #ac050f

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.

At this chroma the association is amplified — it will dominate anything placed beside it, so give it space and use it sparingly. 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
  • EnergyHigh
  • Weight65/100
  • 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#05ACA2
Analogous left#AC0563
Analogous right#AC4E05
Split-complement 1#05AC4E
Split-complement 2#0563AC
Triadic 1#0FAC05
Triadic 2#050FAC
Tetradic#63AC05
On the wheel
Base+30°−30°+120°+240°+180°356°

#ac050f sits at 356°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red67.5%
Green2.0%
Blue5.9%
R · 0–255
172
0xac
G · 0–255
5
0x05
B · 0–255
15
0x0f

CMYK percentages

Cyan0.0%
Magenta97.1%
Yellow91.3%
Key (black)32.5%

Total ink coverage is 221%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#ac050f text on a black background

contrast 2.78:1

Card sample

#ac050f text on a white background

contrast 7.55:1

Card sample

#ac050f on grey

6.89:1

#ac050f on its own surface

6.94:1

#ac050f on its dark surface

2.35:1

CSS3 live lab

Text font color

The quick brown fox

color: #ac050f;
Background color
Panel with #ac050f background
background-color: #ac050f;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #ac050f;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(172, 5, 15, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(172, 5, 15, 0.45);
Border & gradient
Gradient panel
border: 3px solid #ac050f;
background: linear-gradient(135deg, #ac050f, #AC6A05);
Gradient text

Gradient headline

background: linear-gradient(90deg, #ac050f, #AC9405);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #ac050f;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #ac050f;
caret-color: #ac050f;
Left rule
Pull quote or callout
border-left: 4px solid #ac050f;
Ring + tint
Selected chip
background: #FEE6E8;
box-shadow: inset 0 0 0 2px #ac050f;
Conic badge
68%
background: conic-gradient(#ac050f 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #ac050f 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, 5, 15, 0.5)
rgb(172 5 15 / 50%)
#ac050f80
hsl(356 94% 35% / 50%)
color-mix(in srgb, #ac050f 50%, transparent)
Alpha8-digit hexFlat on white
10%#ac050f1a#F7E6E7
20%#ac050f33#EECDCF
40%#ac050f66#DE9B9F
60%#ac050f99#CD696F
80%#ac050fcc#BD373F

Gradients from #ac050f

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, #E80714, #ac050f 45%, #7C040B);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #ac050f, #8E6304);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #ac050f, #05ACA2);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #F81522 0%, #ac050f 45%, #7C040B 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%, #DE0691 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #CA6C06 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #7C040B 0%, transparent 65%), #ac050f;

Monochromatic scale

Palettes built from #ac050f

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.

#ac050f 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

Too dim on dark surfaces at 2.78:1 — lift it to #EC0715 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.

#ac050f, answered

What color is #ac050f?

#ac050f is a dark electric red, closest to Firebrick (ΔE2000 3.7). It sits at 356° on the hue wheel with 94% saturation and 35% lightness, which reads as warm.

What is the RGB value of #ac050f?

rgb(172, 5, 15) — 172 red, 5 green and 15 blue out of 255, or 67.5% / 2% / 5.9% by channel.

What is #ac050f in HSL and HSV?

hsl(356, 94%, 35%) and hsv(356, 97%, 67%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #ac050f a light or a dark color?

It is a dark color. Relative luminance is 0.0891 and perceived brightness is 37%, so white text on it reaches 7.55:1.

Should I use black or white text on #ac050f?

White. It scores 7.55:1 against #ac050f, versus 2.78:1 for black — AAA at any size.

Is #ac050f accessible on a white background?

#ac050f on white scores 7.55:1, which clears AAA at every size.

What is the complementary color of #ac050f?

#05ACA2 sits directly opposite on the wheel. Softer options are the split-complements #05AC4E and #0563AC, which give the same contrast with far less vibration.

What colors go well with #ac050f?

For interface work: #FAF4F5 as the surface, #EDC0C2 for borders, #9B4B4F for secondary text, #01CB8D as an accent and #7C040B for hover and pressed states. For a palette, the analogous pair #AC0563 and #AC4E05 stays calm, while #05ACA2 is the loudest partner.

What is #ac050f in CMYK for printing?

cmyk(0%, 97%, 91%, 33%). 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 #ac050f 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 #AC2B05; nudged cooler, #AE034C.

Which Tailwind color is closest to #ac050f?

The red family — its 500 step is #ef4444, ΔE2000 18.7 away. That is a visible difference, so define #ac050f as a custom token rather than reaching for the built-in.

How do I use #ac050f in Tailwind CSS?

Inline it as an arbitrary value with bg-[#ac050f] or text-[#ac050f], 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 #ac050f with 50% opacity?

rgba(172, 5, 15, 0.5), or #ac050f80 in eight-digit hex. Over white that composites to #D68287; over black, #560308.

Is #ac050f a web-safe color?

No. The nearest web-safe colour is #990000, ΔE2000 4.2 away. The palette only matters for legacy displays and some email clients now.

What does the color #ac050f 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 #ac050f?

The safest is same-hue elevation: linear-gradient(135deg, #E80714, #ac050f 45%, #7C040B). For more colour, a short hue run to #8E6304 keeps it rich without turning muddy.

Work with #ac050f in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #ac050f at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.