CSS named colour

Red

#ff0000

A CSS named colour: red is valid anywhere a colour is expected.

RGB: rgb(255 0 0)
HSL: 0°, 100%, 50%
OKLCh: 62.8% 0.258 29.2

Red in every format

Web & CSSThe everyday formats for stylesheets and design tools.

Hex	`#ff0000`
RGB	`rgb(255 0 0)`
RGB legacy	`rgb(255, 0, 0)`
RGB percent	`rgb(100% 0% 0%)`
HSL	`hsl(0 100% 50%)`
HSL legacy	`hsl(0, 100%, 50%)`
HSV / HSB	`hsv(0, 100%, 100%)`
HWB	`hwb(0 0% 0%)`
Nearest name	`red`
CMYK	`cmyk(0%, 100%, 100%, 0%)`Naive conversion. Real print work needs an ICC profile.

Perceptual & wide gamutModern CSS colour spaces for uniform scales and P3 displays.

OKLCh	`oklch(62.796% 0.25768 29.234)`Modern CSS colour space for even palettes — better than HSL when building scales.
OKLab	`oklab(62.796% 0.22486 0.12585)`
CIE LCh	`lch(54.291% 106.837 40.858)`
CIE Lab	`lab(54.291% 80.805 69.891)`
Display P3	`color(display-p3 0.9175 0.2003 0.1386)`
Rec. 2020	`color(rec2020 0.792 0.231 0.0738)`
srgb-linear	`color(srgb-linear 1 0 0)`Light-linear sRGB — the same numbers a shader wants for maths.
CIE XYZ (D65)	`color(xyz-d65 0.4124 0.2126 0.0193)`

ShadersGLSL, HLSL and WGSL vectors in both encoded and linear form.

GLSL vec3 — sRGB	`vec3(1.0, 0.0, 0.0)`Encoded values. Use when writing straight to the framebuffer.
GLSL vec3 — linear	`vec3(1.0, 0.0, 0.0)`Light-linear values. Use for lighting, blending and mixing.
GLSL vec4 — sRGB	`vec4(1.0, 0.0, 0.0, 1.0)`
GLSL vec4 — linear	`vec4(1.0, 0.0, 0.0, 1.0)`
GLSL ivec3	`ivec3(255, 0, 0)`
HLSL float3 — sRGB	`float3(1.0, 0.0, 0.0)`
HLSL float3 — linear	`float3(1.0, 0.0, 0.0)`
HLSL float4 — sRGB	`float4(1.0, 0.0, 0.0, 1.0)`
HLSL half4 — sRGB	`half4(1.0, 0.0, 0.0, 1.0)`
WGSL vec3f — sRGB	`vec3f(1.0, 0.0, 0.0)`
WGSL vec4f — sRGB	`vec4f(1.0, 0.0, 0.0, 1.0)`
WGSL vec3<f32> — linear	`vec3<f32>(1.0, 0.0, 0.0)`

Engines & appsConstructors for Unity, Unreal, Godot, Flutter, SwiftUI and Android.

Unity Color	`new Color(1.0f, 0.0f, 0.0f, 1.0f)`Color for everyday scripting (0–1). Color32 when you need whole numbers from 0 to 255.
Unity Color32	`new Color32(255, 0, 0, 255)`
Unreal FLinearColor	`FLinearColor(1.0f, 0.0f, 0.0f, 1.0f)`FLinearColor for materials and lighting. FColor when you need whole numbers from 0 to 255.
Unreal FColor	`FColor(255, 0, 0, 255)`Whole numbers from 0 to 255 — use when an API asks for FColor, not FLinearColor.
Godot Color	`Color(1, 0, 0, 1)`
Flutter Color	`Color(0xFFFF0000)`Packed ARGB, so alpha comes first.
Android Color	`Color.rgb(255, 0, 0)`
SwiftUI Color	`Color(red: 1, green: 0, blue: 0)`
UIKit UIColor	`UIColor(red: 1, green: 0, blue: 0, alpha: 1)`

Raw valuesPacked integers and plain arrays.

0x hex	`0xFF0000`
0x hex (ARGB)	`0xFFFF0000`
Array 0–1	`[1, 0, 0]`
Array 0–255	`[255, 0, 0]`
Decimal integer	`16711680`

Contrast and accessibility

WCAG 2 ratios are what audits and legislation reference. APCA is shown alongside because WCAG 2 is known to misjudge mid-tone backgrounds, and it is the basis of the WCAG 3 draft.

Pairing	WCAG 2 ratio	Level	APCA	Suitable for
Red on white	4.00:1	AA Large	Lc 64	Headings and large text
Red on black	5.25:1	AA	Lc 38	Non-text elements only

Red text on a white background

Red text on a black background

White text on Red

Black text on Red

Tonal scale

Hue held fixed while lightness walks OKLCh, ready to use as a design system ramp.

50#fff0eb
100#ffe2db
200#ffcabf
300#ffa798
400#ff7260
500#ff0e08
600#dd0000
700#b40000
800#920000
900#750000
950#490000

Tints and shades

Mixed perceptually toward white and black, so the steps feel evenly spaced.

Tint 1#ff5544
Tint 2#ff7e6c
Tint 3#ffa191
Tint 4#ffc1b6
Tint 5#ffe1da
Shade 1#c80000
Shade 2#940000
Shade 3#630000
Shade 4#360000
Shade 5#0f0000

Colours that work with Red

Complementary, triadic and analogous partners, rotated in OKLCh so they keep the same apparent brightness.

#009cb2
#00a836
#5577ff
#f50084
#d06800

Closest CSS names

redexact match
orangeredΔEok 0.050
crimsonΔEok 0.077
tomatoΔEok 0.093
indianredΔEok 0.117
chocolateΔEok 0.126