red

#FF0000

CSS color

Overview

Red is one of the three additive primary colors, defined at rgb(255, 0, 0) with the red channel fully lit and green and blue extinguished. Its hex value #FF0000 anchors the 0-degree position on the HSV hue wheel at full saturation and brightness. Alongside green and blue, red forms the basis of the RGB model that drives screens and digital imaging; combining it with green yields yellow, and with blue yields magenta. Red is among the sixteen basic HTML colors and one of the most widely recognized CSS keywords. As a long-wavelength color at roughly 700 nanometers, it is the most saturated hue the eye readily distinguishes at the warm end of the spectrum.

Red (#FF0000) is pure, maximum-intensity red in the CSS named colour set and web colour standard, defined as the full red channel of the RGB model with zero green or blue. One of the three primary colours of light, it is simultaneously the colour of danger, passion, love, revolution, and vitality across cultures worldwide. In digital design, pure #FF0000 is rarely used directly as its extreme intensity causes halation on screens, but it anchors the entire warm colour spectrum.

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Color Values

HEX

#FF0000

RGB

255, 0, 0

HSL

0.0, 100.0%, 50.0%

HSV

0.0, 100.0%, 100.0%

CMYK

0.0%, 100.0%, 100.0%, 0.0%

OKLCH

0.628 0.2577 29.2

Properties

Warm Light Nearest: red

Color Psychology

Pure red is the color of adrenaline, passion, and urgency. It raises heart rate and stimulates appetite, which is why fast-food chains and sale banners rely on it worldwide. Culturally, red signifies luck and prosperity in East Asia while representing danger and prohibition in Western road signage.

Design Usage

Medium red is ideal for call-to-action buttons, sale badges, and notification dots where instant attention is needed. It should be used sparingly as an accent rather than a dominant background to avoid visual fatigue. Red pairs effectively with white text for maximum legibility in buttons and banners.

Color Harmonies

Color Blindness Simulation

CSS Usage

background-color: #FF0000;
color: #FF0000;
border-color: #FF0000;
Nearest Tailwind: Red 600 #DC2626

Tailwind Shades

Contrast Checker

Text on white

4.0:1

AA Fail AAA Fail

Text on black

5.25:1

AA Pass AAA Fail

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Brands Using This Color

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Frequently Asked Questions

What are the RGB, HSL, and CMYK values of #FF0000?

RGB(255, 0, 0) · HSL(0.0, 100.0%, 50.0%) · CMYK(0.0%, 100.0%, 100.0%, 0.0%)

Does #FF0000 meet WCAG contrast on white?

4.0:1 — WCAG AA Fail, AAA Fail for normal text.

What text color is readable on #FF0000?

Use 000000 text on a #FF0000 background; contrast on black is 5.25:1.