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#e01721

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

RGB
224, 23, 33
HSL
357°, 81%, 48%
CMYK
0, 90, 85, 12
Luminance
0.1657

At a glance

Every number on this page in one read: what #e01721 is made of, how bright it looks, and which way it leans.

Hex
#e01721
Hue
357°
red
Saturation
81%
electric
Lightness
48%
balanced
Brightness
88%
HSV value
Perceived
49%
weighted brightness
Luminance
0.1657
WCAG relative
Temperature
Warm
18/100 cool
Color family
Red
Tone
Electric
Best ink
White
4.87:1
Closest name
Crimson
ΔE2000 7.2
Where it sits
Hue357° of 360°
Saturation81%
Lightness48%
Temperature
Warm ← → Cool18% cool

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

Every format

HEX#e01721
RGBrgb(224, 23, 33)
HSLhsl(357, 81%, 48%)
CMYKcmyk(0%, 90%, 85%, 12%)
LABlab(47.7 70.7 49.5)
LCHlch(47.7 86.3 35.0)
OKLCHoklch(0.577 0.226 26.8)
Decimal14685985
Display P3color(display-p3 0.878 0.090 0.129)

Copy-ready code

/* CSS */
color: #e01721;
background-color: #e01721;
/* Tailwind (arbitrary) */
class="text-[#e01721] bg-[#e01721]"
/* SCSS */
$brand: #e01721;
/* SwiftUI */
Color(red: 0.878, green: 0.090, blue: 0.129)
/* Android */
Color.parseColor("#e01721")
/* Flutter */
Color(0xFFE01721)
/* Python / OpenCV (BGR) */
(33, 23, 224)

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 #e01721 · 4.87:1
Use #ffffffAA at every size, AAA for large text only.
Aa
White text · 4.87:1 · recommended
AA pass · AA large pass · AAA fail
Aa
Black text · 4.31:1
AA fail · AA large pass · AAA fail
Reading the other direction: #e01721 as text scores 4.87:1 on white and 4.31:1 on black.

Accessibility — WCAG contrast

Aa
#e01721 on white: 4.87:1
AA ✓ pass · AA-large · AAA
Aa
#e01721 on black: 4.31:1
AA ✗ fail · AA-large · AAA
true color
protanopia · #61561E
deuteranopia · #908013
tritanopia · #F70020

Color scale — 50 to 950

A Tailwind-shaped ramp built around this exact hex. #e01721 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.

#FCF2F3
#F9E6E7
#F6C6C8
#F5999E
#EF666D
#EA333D
#e01721
#B9131B
#940F16
#6B0F14
#430A0C
Base = 600Lightest = 50 · #FCF2F3Darkest = 950 · #430A0C
:root {
  --brand-50: #FCF2F3;
  --brand-100: #F9E6E7;
  --brand-200: #F6C6C8;
  --brand-300: #F5999E;
  --brand-400: #EF666D;
  --brand-500: #EA333D;
  --brand-600: #e01721;
  --brand-700: #B9131B;
  --brand-800: #940F16;
  --brand-900: #6B0F14;
  --brand-950: #430A0C;
  --brand: #e01721;
  --brand-ink: #ffffff;
}

Colors that work with #e01721

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#0FBD89
Second voice, not a rival
Dark variant#740C11
Hover, pressed, headers
Light variant#FDE8E9
Selected rows, tints
Dark surface#241414
Dark-mode background
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

How to use #e01721

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
Use with care
  • Full-page backgrounds — tiring over long sessions
  • Pairing with a same-lightness hue — edges vibrate

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#17E0D6
Analogous left#E01785
Analogous right#E07117
Split-complement 1#17E071
Split-complement 2#1785E0
Triadic 1#21E017
Triadic 2#1721E0
Tetradic#85E017

RGB percentages

Red87.8%
Green9.0%
Blue12.9%

CMYK percentages

Cyan0.0%
Magenta89.7%
Yellow85.3%
Key (black)12.2%

Color previews

#e01721 text on a black background

contrast 4.31:1

Card sample

#e01721 text on a white background

contrast 4.87:1

Card sample

CSS3 live lab

Text font color

The quick brown fox

color: #e01721;
Background color
Panel with #e01721 background
background-color: #e01721;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #e01721;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(224, 23, 33, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(224, 23, 33, 0.45);
Border & gradient
Gradient panel
border: 3px solid #e01721;
background: linear-gradient(135deg, #e01721, #E09317);

Monochromatic scale

Palettes built from #e01721

Shades — darker

Tints — lighter

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.

#e01721 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.

#e01721, answered

What color is #e01721?

#e01721 is a balanced electric red, closest to Crimson (ΔE2000 7.2). It sits at 357° on the hue wheel with 81% saturation and 48% lightness, which reads as warm.

What is the RGB value of #e01721?

rgb(224, 23, 33) — 224 red, 23 green and 33 blue out of 255, or 87.8% / 9% / 12.9% by channel.

Is #e01721 a light or a dark color?

It is a dark color. Relative luminance is 0.1657 and perceived brightness is 49%, so white text on it reaches 4.87:1.

Should I use black or white text on #e01721?

White. It scores 4.87:1 against #e01721, versus 4.31:1 for black — AA at any size.

What is the complementary color of #e01721?

#17E0D6 sits directly opposite on the wheel. Softer options are the split-complements #17E071 and #1785E0, which give the same contrast with far less vibration.

What colors go well with #e01721?

For interface work: #FAF4F5 as the surface, #EDC0C2 for borders, #9B4B4F for secondary text, #0FBD89 as an accent and #740C11 for hover and pressed states. For a palette, the analogous pair #E01785 and #E07117 stays calm, while #17E0D6 is the loudest partner.

What is #e01721 in CMYK for printing?

cmyk(0%, 90%, 85%, 12%). 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 #e01721 warm or cool?

Warm — it scores 18 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #E04117; nudged cooler, #E2146A.

Work with #e01721 in the Color Lab