Simple way to apply each folder opening a unique color

folder-window-color.js

setInterval(() => {
  // From https://stackoverflow.com/questions/8022885/rgb-to-hsv-color-in-javascript
  function hslToRgb(h, s, l) {
    var r, g, b;

    if (s == 0) {
      r = g = b = l; // achromatic
    } else {
      function hue2rgb(p, q, t) {
        if (t < 0) t += 1;
        if (t > 1) t -= 1;
        if (t < 1 / 6) return p + (q - p) * 6 * t;
        if (t < 1 / 2) return q;
        if (t < 2 / 3) return p + (q - p) * (2 / 3 - t) * 6;
        return p;
      }

      var q = l < 0.5 ? l * (1 + s) : l + s - l * s;
      var p = 2 * l - q;

      r = hue2rgb(p, q, h + 1 / 3);
      g = hue2rgb(p, q, h);
      b = hue2rgb(p, q, h - 1 / 3);
    }

    return [r * 255 | 0, g * 255 | 0, b * 255 | 0];
  }

  // From https://stackoverflow.com/questions/6122571/simple-non-secure-hash-function-for-javascript
  function stringHash(s) {
    var hash = 0;
    if (s.length == 0) {
      return hash;
    }
    for (var i = 0; i < s.length; i++) {
      var char = s.charCodeAt(i);
      hash = ((hash << 5) - hash) + char;
      hash = hash & hash; // Convert to 32bit integer
    }
    return hash;
  }

  // Main start
  function normalize(start, end, t) {
    return start + t * (end - start)
  }

  let cssEl = document.getElementById('window-color-override')
  if (!cssEl) {
    cssEl = document.createElement('style')
    cssEl.id = 'window-color-override'
    document.head.appendChild(cssEl)
  }

  const title = document.getElementsByClassName('window-title')[0].innerText
  const matches1 = title.match(/^.* - (.* - Visual Studio Code)( \[Unsupported\])?$/)
  const matches2 = title.match(/^(● )?(.* - Visual Studio Code)( \[Unsupported\])?$/)
  const hashPart =
    matches1 ? matches1[1] :
      matches2 ? matches2[2] :
        null

  if (!hashPart) {
    cssEl.innerHTML = ''
    return
  }


  const salt1 = 'title-bar'
  const hash1 = stringHash(salt1 + hashPart)
  const h1 = normalize(0, 1, (hash1 & 0xFFFF0000) / 0x100000000)
  const s1 = normalize(0.2, 0.6, (hash1 & 0xFF00) / 0x10000)
  const l1 = normalize(0.25, 0.35, (hash1 & 0xFF) / 0x100)
  const [titleR, titleG, titleB] = hslToRgb(h1, s1, l1)

  const salt2 = 'activity-bar'
  const hash2 = stringHash(salt2 + hashPart)
  const h2 = h1 + normalize(-0.1, 0.1, (hash2 & 0xFFFF0000) / 0x100000000)
  const s2 = s1 + normalize(-0.1, 0.1, (hash2 & 0xFF00) / 0x10000)
  const l2 = l1 + normalize(-0.05, 0, (hash2 & 0xFF) / 0x100)
  const [activityR, activityG, activityB] = hslToRgb(h2, s2, l2 - 0.1)

  const css = `
  #workbench\\.parts\\.titlebar {
    background-color: rgb(${titleR}, ${titleG}, ${titleB}) !important;
  }

  #workbench\\.parts\\.activitybar {
    background-color: rgb(${activityR}, ${activityG}, ${activityB}) !important;
  }
  `

  cssEl.innerHTML = css
}, 1000)