title: Apexcharts cannot use css variables as fill colors
body: <p>I have tried several methods but no success at <code>fill colors</code>.</p>
  <p>While I thought apexcharts couldn't use css variables as setting values, the following <code>stroke colors</code> work fine.</p>
  <p>css</p>
  <pre><code>:root {
    --bs-warning: #ffc107;
  }
  </code></pre>
  <p>js</p>
  <pre><code>var colors = getComputedStyle(document.documentElement).getPropertyValue('--bs-warning');
  console.log(colors); // #ffc107
  
  var options = {
    chart: {
      type: 'area',
      sparkline: {
        enabled: true,
      },
    },
    fill: {
      colors: colors, // not working
      // or
      colors: '--bs-warning', // not working
      // or
      colors: 'var(--bs-warning)', // not working
  
      // but
      colors: '#ffc107', // Why this working???
  
      stroke: {
        colors: [colors], // hey, this working too but only within array! why?
      },
      // other config
      type: 'solid',
      opacity: 0.5,
    }
  }
  </code></pre>