CodePen Home CSS filter generator to convert from black to target hex color

by Intesar Haider

HTML

<table>
  <tr valign="top">
    <td width="50%">
      <fieldset>
        <p>
          <label>Target color</label> <input class="target" type="text" placeholder="target hex" value="#00a4d6"/>
        </p>
        <button class="execute">Compute Filters</button>
      </fieldset>
      <p>Real pixel, color applied through CSS <code>background-color</code>:</p>
      <div class="pixel realPixel"></div>

      <p>Filtered pixel, color applied through CSS <code>filter</code>:</p>
      <div class="pixel filterPixel"></div>

      <p class="filterDetail"></p>
      <p class="lossDetail"></p>
    </td>
    <td>
      <p>The goal was to be able to create custom style sheets and allow for the coloring of icons</p>
      <p>For this code to work well the starting color needs to be black. If your icon set isn't black you can prepend "brightness(0) saturate(100%)" to your filter property which will first turn the icon set to black.</p>
      <p>
        For as long as I worked on creating this solution from multiple resources I found some had spent far
        longer to create this already completed solution. Only slightly modified to focus on HEX colors. Credit
        goes to MultiplyByZer0 for their post <a href="https://stackoverflow.com/a/43960991/604861" target="_blank">https://stackoverflow.com/a/43960991/604861</a>
      </p>
    </td>
  </tr>
</table>

CSS

.pixel {
  display: inline-block;
  background-color: #000;
  width: 50px;
  height: 50px;
}

.filterDetail {
  font-family: "Consolas", "Menlo", "Ubuntu Mono", monospace;
}

JavaScript

'use strict';

class Color {
  constructor(r, g, b) {
    this.set(r, g, b);
  }
  
  toString() {
    return `rgb(${Math.round(this.r)}, ${Math.round(this.g)}, ${Math.round(this.b)})`;
  }

  set(r, g, b) {
    this.r = this.clamp(r);
    this.g = this.clamp(g);
    this.b = this.clamp(b);
  }

  hueRotate(angle = 0) {
    angle = angle / 180 * Math.PI;
    const sin = Math.sin(angle);
    const cos = Math.cos(angle);

    this.multiply([
      0.213 + cos * 0.787 - sin * 0.213,
      0.715 - cos * 0.715 - sin * 0.715,
      0.072 - cos * 0.072 + sin * 0.928,
      0.213 - cos * 0.213 + sin * 0.143,
      0.715 + cos * 0.285 + sin * 0.140,
      0.072 - cos * 0.072 - sin * 0.283,
      0.213 - cos * 0.213 - sin * 0.787,
      0.715 - cos * 0.715 + sin * 0.715,
      0.072 + cos * 0.928 + sin * 0.072,
    ]);
  }

  grayscale(value = 1) {
    this.multiply([
      0.2126 + 0.7874 * (1 - value),
      0.7152 - 0.7152 * (1 - value),
      0.0722 - 0.0722 * (1 - value),
      0.2126 - 0.2126 * (1 - value),
      0.7152 + 0.2848 * (1 - value),
      0.0722 - 0.0722 * (1 - value),
      0.2126 - 0.2126 * (1 - value),
      0.7152 - 0.7152 * (1 - value),
      0.0722 + 0.9278 * (1 - value),
    ]);
  }

  sepia(value = 1) {
    this.multiply([
      0.393 + 0.607 * (1 - value),
      0.769 - 0.769 * (1 - value),
      0.189 - 0.189 * (1 - value),
      0.349 - 0.349 * (1 - value),
      0.686 + 0.314 * (1 - value),
      0.168 - 0.168 * (1 - value),
      0.272 - 0.272 * (1 - value),
      0.534 - 0.534 * (1 - value),
      0.131 + 0.869 * (1 - value),
    ]);
  }

  saturate(value = 1) {
    this.multiply([
      0.213 + 0.787 * value,
      0.715 - 0.715 * value,
      0.072 - 0.072 * value,
      0.213 - 0.213 * value,
      0.715 + 0.285 * value,
      0.072 - 0.072 * value,
      0.213 - 0.213 * value,
      0.715 - 0.715 * value,
      0.072 + 0.928 * value,
    ]);
  }

  multiply(matrix) {
    const newR = this.clamp(this.r * matrix[0] + this.g * matrix[1] +...