CSS Color

#example-element {
  background-color: #963770;
  color: white;
  padding: 1em;
}

<section class="default-example" id="default-example">
  <p id="example-element">
    London. Michaelmas term lately over, and the Lord Chancellor sitting in
    Lincoln's Inn Hall. Implacable November weather. As much mud in the streets
    as if the waters had but newly retired from the face of the earth, and it
    would not be wonderful to meet a Megalosaurus, forty feet long or so,
    waddling like an elephantine lizard up Holborn Hill.
  </p>
</section>

:root {
  --my-color: oklch(60% 0.25 315 / 0.3);

  /* Same color, but with alpha set to 80% */
  --my-color-80: alpha(from var(--my-color) / 80%);
}

.box1 {
  background-color: var(--my-color);
}

.box2 {
  background-color: var(--my-color-80);
}

body {
  font-family: sans-serif;
  display: flex;
  gap: 10%;
  justify-content: center;
}

div {
  width: 40%;
  height: 100px;
  display: flex;
  justify-content: center;
  align-items: center;
}

<div class="box1">Original</div>
<div class="box2">Fixed 80% alpha</div>

ul {
  display: flex;
  list-style-type: none;
  font-size: 150%;
  gap: 10px;
  border: 2px solid;
  padding: 10px;
}

li {
  padding: 10px;
  flex: 1;
  box-sizing: border-box;
  font-family: monospace;
  outline: 3px solid #a71e14;
  text-align: center;
}

li:nth-child(1) {
  background-color: color-mix(in oklab, #a71e14 0%, white);
}

li:nth-child(2) {
  background-color: color-mix(in oklab, #a71e14 25%, white);
}

li:nth-child(3) {
  background-color: color-mix(in oklab, #a71e14 50%, white);
}

li:nth-child(4) {
  background-color: color-mix(in oklab, #a71e14 75%, white);
}

li:nth-child(5) {
  background-color: color-mix(in oklab, #a71e14 100%, white);
}

li:nth-child(6) {
  background-color: color-mix(in oklab, #a71e14, white);
}

<ul>
  <li>0%</li>
  <li>25%</li>
  <li>50%</li>
  <li>75%</li>
  <li>100%</li>
  <li></li>
</ul>

div {
  width: 50px;
  height: 50px;
  padding: 5px;
  margin: 5px;
  display: inline-block;
  border: 1px solid black;
}

[data-color="red-a98-rgb"] {
  background-color: color(a98-rgb 1 0 0);
}
[data-color="red-prophoto-rgb"] {
  background-color: color(prophoto-rgb 1 0 0);
}
/* sRGB gamut, linear-light — full brightness (green channel 100%) */
[data-color="green-srgb-linear"] {
  background-color: color(srgb-linear 0 1 0);
}
/* P3 gamut (wider), gamma-encoded — low brightness (green channel ~21% light output) */
[data-color="green-display-p3"] {
  background-color: color(display-p3 0 0.5 0);
}
/* P3 gamut (wider), linear-light — half brightness (green channel at 50% light output) */
[data-color="green-display-p3-linear"] {
  background-color: color(display-p3-linear 0 0.5 0);
}
[data-color="blue-rec2020"] {
  background-color: color(rec2020 0 0 1);
}
[data-color="blue-srgb"] {
  background-color: color(srgb 0 0 1);
}

<div data-color="red-a98-rgb"></div>
<div data-color="red-prophoto-rgb"></div>
<div data-color="green-srgb-linear"></div>
<div data-color="green-display-p3"></div>
<div data-color="green-display-p3-linear"></div>
<div data-color="blue-rec2020"></div>
<div data-color="blue-srgb"></div>

:root {
  --button-color: lightblue;
}

button {
  background-color: var(--button-color);

  /* Set contrasting text color automatically */
  color: contrast-color(var(--button-color));
}

body {
  padding: 1rem;
}

button {
  margin: 3rem;
  padding: 1rem;
  width: 150px;
  font-size: 2rem;
  border-radius: 1rem;
}

@supports not (color: contrast-color(red)) {
  body::before {
    content: "Your browser doesn't support the contrast-color() function.";
    background-color: wheat;
    display: block;
    text-align: center;
    padding: 1rem 0;
  }
}

<label>
  Select background color of the button:
  <input type="color" id="colorPicker" value="#660066" />
</label>
<br />
<button>Button</button>

const colorPicker = document.getElementById("colorPicker");
const root = document.documentElement;

function updateColor(color) {
  root.style.setProperty("--button-color", colorPicker.value);
}

colorPicker.addEventListener("input", updateColor);
updateColor();

#example-element {
  min-width: 100%;
  min-height: 100%;
  padding: 10%;
}

<section id="default-example">
  <div class="transition-all" id="example-element"></div>
</section>

#example-element {
  min-width: 100%;
  min-height: 100%;
  padding: 10%;
}

<section id="default-example">
  <div class="transition-all" id="example-element"></div>
</section>

body {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
div {
  height: 50px;
  flex: 0 0 28%;
  border: 1px solid black;
}

[data-color="red-dark"] {
  background-color: lab(5 125 71);
}
[data-color="red"] {
  background-color: lab(40 125 71);
}
[data-color="red-light"] {
  background-color: lab(95 125 71);
}

[data-color="green-dark"] {
  background-color: lab(10% -120 125);
}
[data-color="green"] {
  background-color: lab(50% -120 125);
}
[data-color="green-light"] {
  background-color: lab(90% -120 125);
}

[data-color="blue-dark"] {
  background-color: lab(10 -120 -120);
}
[data-color="blue"] {
  background-color: lab(50 -120 -120);
}
[data-color="blue-light"] {
  background-color: lab(90 -120 -120);
}

<div data-color="red-dark"></div>
<div data-color="red"></div>
<div data-color="red-light"></div>

<div data-color="green-dark"></div>
<div data-color="green"></div>
<div data-color="green-light"></div>

<div data-color="blue-dark"></div>
<div data-color="blue"></div>
<div data-color="blue-light"></div>

body {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 20px;
}
div {
  height: 50px;
  border: 1px solid black;
}

[data-color="blue-dark"] {
  background-color: lch(10% 100 240);
}
[data-color="blue"] {
  background-color: lch(50% 100 240);
}
[data-color="blue-light"] {
  background-color: lch(90% 100 240);
}

[data-color="red-dark"] {
  background-color: lch(10% 130 20);
}
[data-color="red"] {
  background-color: lch(50% 130 20);
}
[data-color="red-light"] {
  background-color: lch(90% 130 20);
}

[data-color="green-dark"] {
  background-color: lch(10% 132 130);
}
[data-color="green"] {
  background-color: lch(50% 132 130);
}
[data-color="green-light"] {
  background-color: lch(90% 132 130);
}

<div data-color="blue-dark"></div>
<div data-color="blue"></div>
<div data-color="blue-light"></div>

<div data-color="red-dark"></div>
<div data-color="red"></div>
<div data-color="red-light"></div>

<div data-color="green-dark"></div>
<div data-color="green"></div>
<div data-color="green-light"></div>

:root {
  /* this has to be set to switch between light or dark */
  color-scheme: light dark;

  --light-bg: ghostwhite;
  --light-color: darkslategray;
  --light-code: tomato;

  --dark-bg: darkslategray;
  --dark-color: ghostwhite;
  --dark-code: gold;
}
* {
  background-color: light-dark(var(--light-bg), var(--dark-bg));
  color: light-dark(var(--light-color), var(--dark-color));
}
code {
  color: light-dark(var(--light-code), var(--dark-code));
}

.light {
  /* forces light color-scheme */
  color-scheme: light;
}
.dark {
  /* forces dark color-scheme */
  color-scheme: dark;
}

section {
  padding: 0.8rem;
}

<h1><code>light-dark()</code> CSS function</h1>
<section>
  <h2>Automatic</h2>
  <p>This section will react to the users system or user agent setting.</p>
</section>
<section class="light">
  <h2>Light</h2>
  <p>
    This section will be light due to the <code>color-scheme: light;</code>.
  </p>
</section>
<section class="dark">
  <h2>Dark</h2>
  <p>This section will be dark due to the <code>color-scheme: dark;</code>.</p>
</section>

body {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
div {
  height: 50px;
  flex: 0 0 28%;
  border: 1px solid black;
}

[data-color="red-dark"] {
  background-color: oklab(0.05 0.4 0.4);
}
[data-color="red"] {
  background-color: oklab(0.5 0.4 0.4);
}
[data-color="red-light"] {
  background-color: oklab(0.95 0.4 0.4);
}

[data-color="green-dark"] {
  background-color: oklab(5% -100% 0.4);
}
[data-color="green"] {
  background-color: oklab(50% -100% 0.4);
}
[data-color="green-light"] {
  background-color: oklab(95% -100% 0.4);
}

[data-color="blue-dark"] {
  background-color: oklab(0.05 -0.3 -0.4);
}
[data-color="blue"] {
  background-color: oklab(0.5 -0.3 -0.4);
}
[data-color="blue-light"] {
  background-color: oklab(0.95 -0.3 -0.4);
}

<div data-color="red-dark"></div>
<div data-color="red"></div>
<div data-color="red-light"></div>

<div data-color="green-dark"></div>
<div data-color="green"></div>
<div data-color="green-light"></div>

<div data-color="blue-dark"></div>
<div data-color="blue"></div>
<div data-color="blue-light"></div>

body {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 20px;
}
div {
  height: 50px;
  border: 1px solid black;
}

[data-color="blue-dark"] {
  background-color: oklch(10% 0.4 240);
}
[data-color="blue"] {
  background-color: oklch(50% 0.4 240);
}
[data-color="blue-light"] {
  background-color: oklch(90% 0.4 240);
}

[data-color="red-dark"] {
  background-color: oklch(10% 0.4 20);
}
[data-color="red"] {
  background-color: oklch(50% 0.4 20);
}
[data-color="red-light"] {
  background-color: oklch(90% 0.4 20);
}

[data-color="green-dark"] {
  background-color: oklch(10% 0.4 130);
}
[data-color="green"] {
  background-color: oklch(50% 0.4 130);
}
[data-color="green-light"] {
  background-color: oklch(90% 0.4 130);
}

<div data-color="blue-dark"></div>
<div data-color="blue"></div>
<div data-color="blue-light"></div>

<div data-color="red-dark"></div>
<div data-color="red"></div>
<div data-color="red-light"></div>

<div data-color="green-dark"></div>
<div data-color="green"></div>
<div data-color="green-light"></div>

#example-element {
  min-width: 100%;
  min-height: 100%;
  padding: 10%;
}

<section id="default-example">
  <div class="transition-all" id="example-element"></div>
</section>

.gradient {
  height: 50px;
  width: 100%;
}
.srgb {
  background-image: linear-gradient(in srgb to right, blue, red);
}
.oklab {
  background-image: linear-gradient(in oklab to right, blue, red);
}
.oklch-longer {
  background-image: linear-gradient(in oklch longer hue to right, blue, red);
}

<div>sRGB:</div>
<div class="gradient srgb"></div>
<div>Oklab:</div>
<div class="gradient oklab"></div>
<div>Oklch (with <code>longer hue</code>):</div>
<div class="gradient oklch-longer"></div>

div {
  height: 200px;
  width: 200px;
}

<div></div>
<hr />
<label for="color">Enter a valid color value:</label>
<input type="text" id="color" />

const inputElem = document.querySelector("input");
const divElem = document.querySelector("div");

function validTextColor(stringToTest) {
  if (stringToTest === "inherit" || stringToTest === "transparent") {
    return false;
  }

  const div = document.createElement("div");
  div.style.color = stringToTest;
  return !!div.style.color;
}

inputElem.addEventListener("input", () => {
  if (validTextColor(inputElem.value)) {
    divElem.style.backgroundColor = inputElem.value;
    divElem.textContent = "";
  } else {
    divElem.removeAttribute("style");
    divElem.textContent = "Invalid color value";
  }
});

body {
  display: flex;
  justify-content: space-evenly;
  font-family: monospace;
}
div {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

[class] {
  width: 40px;
  height: 40px;
}
.c1 {
  background: #f09;
}
.c2 {
  background: #f09a;
}
.c3 {
  background: #ff0099;
}
.c4 {
  background: #ff0099aa;
}

<div>
  #F09
  <div class="c1"></div>
</div>
<div>
  #f09a
  <div class="c2"></div>
</div>
<div>
  #ff0099
  <div class="c3"></div>
</div>
<div>
  #FF0099AA
  <div class="c4"></div>
</div>

div {
  border: 1px solid black;
  height: 50px;
  margin: 10px;
  width: 90%;
}
p {
  color: white;
  margin: 6px;
}

/* Fallback styles */
.hsl,
.hsl-shorter,
.hsl-named {
  background: linear-gradient(
    to right,
    hsl(39 100% 50%),
    hsl(46 100% 50%),
    hsl(53 100% 50%),
    hsl(60 100% 50%)
  );
}
.hsl-increasing {
  background: linear-gradient(
    to right,
    hsl(190 100% 50%),
    hsl(225 100% 50%),
    hsl(260 100% 50%),
    hsl(295 100% 50%),
    hsl(330 100% 50%),
    hsl(365 100% 50%),
    hsl(400 100% 50%),
    hsl(435 100% 50%),
    hsl(470 100% 50%),
    hsl(505 100% 50%),
    hsl(540 100% 50%)
  );
}
.hsl-decreasing,
.hsl-longer,
.hsl-named-longer {
  background: linear-gradient(
    to right,
    hsl(399 100% 50%),
    hsl(368 100% 50%),
    hsl(337 100% 50%),
    hsl(307 100% 50%),
    hsl(276 100% 50%),
    hsl(245 100% 50%),
    hsl(214 100% 50%),
    hsl(183 100% 50%),
    hsl(152 100% 50%),
    hsl(122 100% 50%),
    hsl(91 100% 50%),
    hsl(60 100% 50%)
  );
}

.hsl {
  background: linear-gradient(
    to right in hsl,
    hsl(39deg 100% 50%),
    hsl(60deg 100% 50%)
  );
}
.hsl-increasing {
  background: linear-gradient(
    to right in hsl increasing hue,
    hsl(190deg 100% 50%),
    hsl(180deg 100% 50%)
  );
}
.hsl-decreasing {
  background: linear-gradient(
    to right in hsl decreasing hue,
    hsl(39deg 100% 50%),
    hsl(60deg 100% 50%)
  );
}
.hsl-shorter {
  background: linear-gradient(
    to right in hsl shorter hue,
    hsl(39deg 100% 50%),
    hsl(60deg 100% 50%)
  );
}
.hsl-longer {
  background: linear-gradient(
    to right in hsl longer hue,
    hsl(39deg 100% 50%),
    hsl(60deg 100% 50%)
  );
}
.hsl-named {
  background: linear-gradient(to right in hsl, orange, yellow);
}
.hsl-named-longer {
  background: linear-gradient(to right in hsl longer hue, orange, yellow);
}

<div class="hsl">
  <p>HSL</p>
</div>
<div class="hsl-increasing">
  <p>HSL increasing</p>
</div>
<div class="hsl-decreasing">
  <p>HSL decreasing</p>
</div>
<div class="hsl-shorter">
  <p>HSL shorter</p>
</div>
<div class="hsl-longer">
  <p>HSL longer</p>
</div>
<div class="hsl-named">
  <p>HSL named</p>
</div>
<div class="hsl-named-longer">
  <p>HSL named (longer)</p>
</div>

div {
  width: 100px;
  height: 100px;
  margin: 10px;
  border: 1px solid black;
}
p {
  font-family: sans-serif;
}
span {
  font-family: monospace;
  background: rgb(0 0 0 / 10%);
  padding: 3px;
}
#hue-slider {
  width: 90%;
}

#box {
  background-color: hsl(0 100% 50%);
}

<input type="range" min="0" max="360" value="0" id="hue-slider" />
<p>Hue: <span id="hue-value">0deg</span></p>
<div id="box"></div>

const hue = document.querySelector("#hue-slider");
const box = document.querySelector("#box");
hue.addEventListener("input", () => {
  box.style.backgroundColor = `hsl(${hue.value} 100% 50%)`;
  document.querySelector("#hue-value").textContent = `${hue.value}deg`;
});

#container {
  display: flex;
  justify-content: space-around;
  background-color: darkslateblue;
  padding: 20px;
}

#container > div {
  height: 100px;
  width: 100px;
  margin: 3px;
  border: 2px solid black;
}

#one {
  background-color: red;
}

#two {
  background-color: lavender;
}

#three {
  background-color: transparent;
}

<div id="container">
  <div id="one"></div>
  <div id="two"></div>
  <div id="three"></div>
</div>

.button {
  border: 0;
  padding: 10px;
  box-shadow:
    -2px -2px 5px gray,
    2px 2px 5px gray;
}

@media (forced-colors: active) {
  .button {
    /* Use a border instead, since box-shadow
    is forced to 'none' in forced-colors mode */
    border: 2px ButtonBorder solid;
  }
}

<button class="button">Press me!</button>