Color Modes (chroma-js)

color-modes-chroma-js.markdown

Color Modes (chroma-js)

the differences in how different color modes interpolate the journey from one color to the next.

A Pen by HARUN PEHLİVAN on CodePen.

License.

index.html

<main>
  <nav>
    <input id="color-a" type="color" value="#00c4ff" />
    <input id="steps" type="number" value="3" min="3" max="24" />
    <input id="color-b" type="color" value="#ff6347" />
  </nav>
  <section></section>
</main>

script.babel

console.clear();

const section = document.querySelector("section");
const nav = document.querySelector("nav");
const colorA = document.getElementById("color-a");
const colorB = document.getElementById("color-b");
const steps = document.getElementById("steps");
const lib = {};

colorA.addEventListener("input", run);
colorB.addEventListener("input", run);
steps.addEventListener("input", run);

run();

function run() {
  const a = colorA.value;
  const b = colorB.value;
  const scales = generateScales(a, b, parseInt(steps.value));
  
  nav.style.background = `linear-gradient(90deg, ${a} 0%, ${a} 49.999%, ${b} 50%, ${b} 100%)`;

  for (let mode in scales) {
    let item = lib[mode];
    let span;
    let ul;
    if (item) {
      span = item.span;
      ul = item.ul;
    } else {
      const div = document.createElement("div");
      span = document.createElement("span");
      ul = document.createElement("ul");
      const p = document.createElement("p");
      p.innerText = mode.toUpperCase();
      div.appendChild(span);
      div.appendChild(ul);
      div.appendChild(p);
      section.appendChild(div);
      lib[mode] = { span, ul };
    }

    const length = scales[mode].length;
    const steps = scales[mode].map((step, i) => `${step} ${(i / (length - 1) * 100).toFixed(3)}%`);
    const background = `linear-gradient(90deg, ${steps.join(", ")})`;
    // ul.innerHTML = scales[mode].map((hex) => `<li><span>${hex}</span></li>`).join("") + `<li><span>${background}</span></li>`;
    ul.innerHTML = `<li><span>${background}</span></li>`;
    span.style.background = background;
  }
}

function generateScales(colorA, colorB, steps = 3) {
  const hsl = chroma.scale([colorA, colorB]).mode("hsl");
  const lab = chroma.scale([colorA, colorB]).mode("lab");
  const lch = chroma.scale([colorA, colorB]).mode("lch");
  const num = chroma.scale([colorA, colorB]).mode("num");
  const rgb = chroma.scale([colorA, colorB]).mode("rgb");

  const res = { lch: [], lab: [], rgb: [], hsl: [], num: [] };
  const step = 1 / (steps - 1);  
  for (let i = 0; i <= steps - 1; i++) {
    const amt = i * step;
    res.hsl.push(hsl(amt).hex());
    res.lab.push(lab(amt).hex());
    res.lch.push(lch(amt).hex());
    res.num.push(num(amt).hex());
    res.rgb.push(rgb(amt).hex());
  }
  return res;
}

scripts

<script src="https://cdnjs.cloudflare.com/ajax/libs/chroma-js/2.1.0/chroma.min.js"></script>

style.css

html, body, main {
  height: 100%;
}

body {
  background: black;
}

main {
  display: flex;
  flex-direction: column;
}

nav {
  display: flex;
  justify-content: center;
}

nav input {
  border: 2px solid #f0f0f0;
  border-radius: 4px;
  margin: 1rem 0.5rem;
}

section {
  display: flex;
  flex-direction: column;
  flex: 1;
}

div {
  flex: 1;
  position: relative;
}

div > span {
  display: block;
  height: 100%;
  width: 100%;
}

div > ul {
  display: flex;
  flex-wrap: wrap;
  left: 0;
  list-style: none;
  margin: 0;
  opacity: 0;
  padding: 0;
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 100%;
}
div:hover > ul {
  opacity: 1;
}
div:hover > p {
  opacity: 0;
}
div > ul li {
  flex: 1;
  font-size: 0.7rem;
  letter-spacing: 0.0625em;
  line-height: 1;
  text-align: center;
}
div > ul li:last-child {
  display: block;
  flex: auto;
/*   margin-top: 1rem; */
  width: 100%;
}
div > ul li span {
  background: white;
  border-radius: 2px;
  padding: 0.125rem;
}
div > p {
  background: white;
  border-radius: 2px;
  display: inline-block;
  font-size: 0.7rem;
  left: 50%;
  letter-spacing: 0.0625em;
  line-height: 1;
  margin: 0;
  padding: 0.25rem;
  position: absolute;
  text-align: center;
  top: 50%;
  transform: translateX(-50%) translateY(-50%);
}