What is the hex code for Red?

Red is #ff0000. In CSS the keyword red, the hex #ff0000, rgb(255, 0, 0) and hsl(0, 100%, 50%) all paint the same color.

What is the opposite of Red on the color wheel?

The opposite (complementary) color is #00ffff, the same saturation and lightness rotated 180° around the HSL wheel. Complementary pairs give the strongest contrast, which is why the complement should be used sparingly rather than at equal weight.

Can I use Red for text?

Red as text on white has a contrast ratio of 4:1, which fails WCAG AA for body text (4.5:1) but passes for large text and UI components (3:1). On black it is 5.25:1, which passes for body text. Use it as text on dark surfaces, or as a fill with dark text on top.

CSS color names · Reds

Red color: hex #ff0000, RGB and HSL

Red is the CSS keyword red, hex #ff0000, rgb(255, 0, 0), hsl(0, 100%, 50%). It is a medium, fully saturated red in the reds family. Below: the colors that go with it, its tints and shades, how it reads as text, and a complete interface palette built from it.

CSS name: red
Hex: #ff0000
RGB: rgb(255, 0, 0)
HSL: hsl(0, 100%, 50%)
On white: 4:1 — large text and UI only (3:1)
On black: 5.25:1 — passes AA for body text

.example {
  color: red;          /* keyword */
  color: #ff0000;          /* hex */
  color: rgb(255, 0, 0); /* rgb */
  color: hsl(0, 100%, 50%); /* hsl */
}

What colors go with red

Each match keeps red's saturation and lightness and rotates only the hue, so the relationship is the wheel's and nothing else. Any of these can be an accent beside red as the primary; the harmony guides explain which rule suits which interface.

Complementary

The opposite hue, 180° away — the strongest contrast, best kept to one accent per screen.

#00ffff · cyan

Split-complementary

The two neighbors of the complement, at 150° and 210° — most of the contrast with less tension, and two accents instead of one.

#00ff80

#0080ff

Triadic

Two hues at 120° and 240° — three evenly spaced signals, the scheme charts and category colors want.

#00ff00 · lime #0000ff · blue

Analogous

The neighbors at −30° and +30° — calm and cohesive, with emphasis coming from weight and size rather than hue.

#ff0080

#ff8000

Tints and shades of red

Tints add lightness toward white; shades remove it toward black. The hue and saturation stay fixed, so every step still reads as red — these are the hover, pressed, disabled and surface variants a single brand color needs.

Tints (lighter)

#ff2b2b

#ff5555

#ff8080

#ffaaaa

#ffd4d4

Shades (darker)

#d40000

#aa0000

#800000 · maroon

#550000

#2b0000

A UI color palette built from red

The eight semantic roles an interface actually uses, derived from red as the primary with the split-complementary rule: secondary and accent rotate around the wheel, and the five neutrals take the hue at lightness steps tuned for light and dark mode. This is the same derivation the palette generator runs — open it there to change the rule, drag the anchors, or export the set as CSS variables.

Light mode

primary: #ff0000
secondary: #00ff80
accent: #0080ff
background: #fdfcfc
surface: #f7f3f3
text: #221111
muted: #8f5656
border: #ecdfdf

Dark mode

primary: #ff1a1a
secondary: #1aff8c
accent: #1a8cff
background: #1b0e0e
surface: #281515
text: #f6f3f3
muted: #b89494
border: #492727

Open red in the palette generator

Using red in an interface

Red is spoken for: it means error, danger and destructive actions in almost every interface, so a red brand color needs its status colors chosen with care. Crimson and firebrick read as serious; the salmons and corals are gentle enough for surfaces and tags. Whichever role red takes, define it once as a token rather than repeating the keyword: the semantic palette guide covers the eight roles, and the guides to complementary, triadic and the other color schemes explain how to weight the matches above.

What is the hex code for Red?: Red is #ff0000. In CSS the keyword red, the hex #ff0000, rgb(255, 0, 0) and hsl(0, 100%, 50%) all paint the same color.
What colors go with Red?: Its complement is #00ffff, the split-complementary pair is #00ff80 and #0080ff, the triadic partners are #00ff00 and #0000ff, and the analogous neighbors are #ff0080 and #ff8000. In an interface, use Red for most colored elements and one of these for a single accent, at roughly an 80/20 split.
What is the opposite of Red on the color wheel?: The opposite (complementary) color is #00ffff, the same saturation and lightness rotated 180° around the HSL wheel. Complementary pairs give the strongest contrast, which is why the complement should be used sparingly rather than at equal weight.
Can I use Red for text?: Red as text on white has a contrast ratio of 4:1, which fails WCAG AA for body text (4.5:1) but passes for large text and UI components (3:1). On black it is 5.25:1, which passes for body text. Use it as text on dark surfaces, or as a fill with dark text on top.