Red #FF0000 colour

#FF0000 is the CSS colour red. RGB 255, 0, 0, HSL 0, 100%, 50%. Black text passes AA (5.25:1), white passes AA for large text (4.00:1).

#FF0000

CSS name: red, one of the 16 original HTML colours
Nearest other: orangered #ff4500
Described as: a vivid red
Red, green, blue: 255, 0, 0
Web safe: Yes, one of the 216 web-safe colours
Luminance: 0.2126 (WCAG relative luminance, 0 is black, 1 is white)

Colour codes

HEX	`#ff0000`
HEX (short)	`#f00`
RGB	`rgb(255, 0, 0)`
RGB (percent)	`rgb(100% 0% 0%)`
HSL	`hsl(0, 100%, 50%)`
HSV / HSB	`hsv(0, 100%, 100%)`
HWB	`hwb(0 0% 0%)`
CMYK (naive)	`cmyk(0%, 100%, 100%, 0%)`
CIELAB (D50)	`lab(54.29% 80.8 69.88)`
OKLCH	`oklch(62.8% 0.2577 29.23)`
Decimal	`16711680`

CMYK here is the plain formula with no colour profile, so treat it as a starting point; a printer's profile gives the real ink values. CIELAB uses a D50 white point, as CSS lab() does. HSV is not a CSS function, so it is shown for design apps only.

Contrast with white and black text

White text, 4.00:1The quick brown fox jumps over the lazy dog.

Black text, 5.25:1The quick brown fox jumps over the lazy dog.

Text	Ratio	AA normal (4.5)	AA large (3)	AAA normal (7)	AAA large (4.5)
White	4.00:1	Fail	Pass	Fail	Fail
Black	5.25:1	Pass	Pass	Fail	Pass

Black text is the better choice on #FF0000 (5.25:1). Ratios use the WCAG 2.2 formula; large text means at least 24px, or 18.66px bold. Check another pair.

Tints and shades

Mixed with white, then with black, in ten even steps (straight sRGB mixing, as most design tools do).

9%#ff1717 18%#ff2e2e 27%#ff4646 36%#ff5d5d 45%#ff7474 55%#ff8b8b 64%#ffa2a2 73%#ffb9b9 82%#ffd1d1 91%#ffe8e8

9%#e80000 18%#d10000 27%#b90000 36%#a20000 45%#8b0000 55%#740000 64%#5d0000 73%#460000 82%#2e0000 91%#170000

Colour harmonies

Hue turned around the HSL colour wheel, saturation and lightness kept.

Complementary

The hue opposite on the colour wheel (180°).

#ff0000 #00ffff

Analogous

Neighbours 30° either side.

#ff0080 #ff0000 #ff8000

Triadic

Three hues 120° apart.

#ff0000 #00ff00 #0000ff

Split complementary

The two hues either side of the complement (150° and 210°).

#ff0000 #00ff80 #0080ff

Tetradic (square)

Four hues 90° apart.

#ff0000 #80ff00 #00ffff #8000ff

How it looks with colour blindness

Normal vision#ff0000 Protanopia#6d5f00 Deuteranopia#a39000 Tritanopia#ff000f Achromatopsia#7f7f7f

Simulated with the Machado, Oliveira and Fernandes (2009) matrices at full severity, applied in linear RGB; achromatopsia shows the colour's luminance as grey. Milder forms (protanomaly, deuteranomaly) are far more common and shift colours less. Never use colour as the only way to carry meaning.

CSS

Text colour	`color: #ff0000;`
Background	`background-color: #ff0000;`
Border	`border: 1px solid #ff0000;`
Half transparent	`background-color: rgb(255 0 0 / 50%);`
Custom property	`--colour-main: #ff0000;`
Gradient to a darker shade	`background: linear-gradient(135deg, #ff0000, #990000);`
Gradient from a lighter tint	`background: linear-gradient(180deg, #ff6666, #ff0000);`
Text on this colour	`background-color: #ff0000; color: #000;`

Similar named colours

Distance is measured in OKLab, scaled by 100; under about 2 is hard to tell apart side by side.

Convert #FF0000 to other formats · Build a palette from it · Check contrast · All named colours

Colour names from CSS Color Module Level 4. Palette values from the Tailwind CSS v3 default palette (MIT licence) and the Material Design 2014 colour palette as published in Material Design Lite (Apache License 2.0). All other values are calculated from the hex code.