#f00321
a balanced, electric red · warm · closest name: Red
At a glance
Every number on this page in one read: what #f00321 is made of, how bright it looks, and which way it leans.
Reads warm. Warm and cool siblings keep the same lightness, so you can swap one in without redoing your contrast maths.
Every format
| HEX | #f00321 |
| RGB | rgb(240, 3, 33) |
| HSL | hsl(352, 98%, 48%) |
| CMYK | cmyk(0%, 99%, 86%, 6%) |
| LAB | lab(50.3 76.6 53.0) |
| LCH | lch(50.3 93.2 34.7) |
| OKLCH | oklch(0.602 0.244 26.3) |
| Decimal | 15729441 |
| Display P3 | color(display-p3 0.941 0.012 0.129) |
Copy-ready code
/* CSS */
color: #f00321;
background-color: #f00321;
/* Tailwind (arbitrary) */
class="text-[#f00321] bg-[#f00321]"
/* SCSS */
$brand: #f00321;
/* SwiftUI */
Color(red: 0.941, green: 0.012, blue: 0.129)
/* Android */
Color.parseColor("#f00321")
/* Flutter */
Color(0xFFF00321)
/* Python / OpenCV (BGR) */
(33, 3, 240)Best text color
Only one of black and white can be right. This is the one, with the number that proves it.
Accessibility — WCAG contrast
Color scale — 50 to 950
A Tailwind-shaped ramp built around this exact hex. #f00321 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.
:root {
--brand-50: #FDF1F3;
--brand-100: #FCE4E7;
--brand-200: #FBC1C8;
--brand-300: #FE909E;
--brand-400: #FD596E;
--brand-500: #FC213D;
--brand-600: #f00321;
--brand-700: #C9031C;
--brand-800: #A10216;
--brand-900: #740614;
--brand-950: #49040D;
--brand: #f00321;
--brand-ink: #000000;
}Colors that work with #f00321
Not a palette — a role sheet. Each swatch answers one question you will hit while building the component.
Surface, border, heading and body all derive from this one hue, so the screen stays coherent without a second palette.
Lightness flips, hue holds. The accent stays the anchor in both themes.
How to use #f00321
Derived from its contrast, chroma and lightness — not from taste.
- ✓Headings from 24px up 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
- ⚠Small text on white — under 4.5:1
- ⚠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 | #03F0D2 | Directly opposite — maximum tension | |
| Analogous left | #F00397 | Neighbour, quieter | |
| Analogous right | #F05B03 | Neighbour, quieter | |
| Split-complement 1 | #03F05B | Contrast without the clash | |
| Split-complement 2 | #0397F0 | Contrast without the clash | |
| Triadic 1 | #21F003 | Even thirds — balanced and loud | |
| Triadic 2 | #0321F0 | Even thirds — balanced and loud | |
| Tetradic | #97F003 | Fourth corner of the square scheme |
RGB percentages
CMYK percentages
Color previews
#f00321 text on a black background
contrast 4.74:1
#f00321 text on a white background
contrast 4.43:1
CSS3 live lab
The quick brown fox
color: #f00321;
background-color: #f00321;
Glowing headline
text-shadow: 2px 2px 8px #f00321;
Soft neon halo
text-shadow: 0 0 14px rgba(240, 3, 33, 0.45);
box-shadow: 0 12px 32px -8px rgba(240, 3, 33, 0.45);
border: 3px solid #f00321; background: linear-gradient(135deg, #f00321, #F08303);
Monochromatic scale
Palettes built from #f00321
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.
Closest color with a full write-up: Vermilion (#e34234) — ΔE2000 4.3 away, with its history, psychology and brand usage.
#f00321 in the real world
Where a color in this family tends to land, and the interface roles it is usually asked to play.
Sits outside most CMYK gamuts — expect a duller press result, or specify a spot ink.
#f00321, answered
What color is #f00321?
#f00321 is a balanced electric red, closest to Red (ΔE2000 5.6). It sits at 352° on the hue wheel with 98% saturation and 48% lightness, which reads as warm.
What is the RGB value of #f00321?
rgb(240, 3, 33) — 240 red, 3 green and 33 blue out of 255, or 94.1% / 1.2% / 12.9% by channel.
Is #f00321 a light or a dark color?
It is a mid-tone. Relative luminance is 0.1870 and perceived brightness is 52%, so black text on it reaches 4.74:1.
Should I use black or white text on #f00321?
Black. It scores 4.74:1 against #f00321, versus 4.43:1 for white — AA at any size.
What is the complementary color of #f00321?
#03F0D2 sits directly opposite on the wheel. Softer options are the split-complements #03F05B and #0397F0, which give the same contrast with far less vibration.
What colors go well with #f00321?
For interface work: #FAF4F5 as the surface, #EDC0C5 for borders, #9B4B55 for secondary text, #00CC7F as an accent and #7E0211 for hover and pressed states. For a palette, the analogous pair #F00397 and #F05B03 stays calm, while #03F0D2 is the loudest partner.
What is #f00321 in CMYK for printing?
cmyk(0%, 99%, 86%, 6%). 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 #f00321 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 #F02803; nudged cooler, #F20178.