title: why I can't fill color to some map area in d3js
body: <p>d3js v7</p>
  <p>using geojson to draw a china map, i can't fill color to any area.</p>
  <pre class="lang-js prettyprint-override"><code>let width = 700;
  let height = 700;
  var projection = d3
    .geoMercator()
    .scale(width * 0.75)
    .center([121, 38]);
  
  var path = d3.geoPath().projection(projection);
  
  var map = d3
    .select(&quot;body&quot;)
    .append(&quot;svg&quot;)
    .attr(&quot;width&quot;, width)
    .attr(&quot;height&quot;, height);
  
  d3.json(
    &quot;https://geo.datav.aliyun.com/areas_v3/bound/geojson?code=100000_full&quot;
  ).then((data: any) =&gt; {
    map
      .selectAll(&quot;path&quot;)
      .data(data.features)
      .enter()
      .append(&quot;path&quot;)
      .attr(&quot;d&quot;, path)
      .attr(&quot;fill&quot;, &quot;none&quot;)
      .attr(&quot;stroke&quot;, &quot;black&quot;);
  });
  
  </code></pre>
  <p>when fill color with <code>none</code>, it can work
  <a href="https://i.stack.imgur.com/Q9Xoz.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Q9Xoz.png" alt="enter image description here" /></a></p>
  <p>when using other color, it fail</p>
  <p><code>attr(&quot;fill&quot;, &quot;#0ea5e9&quot;)</code></p>
  <p><a href="https://i.stack.imgur.com/4te2Q.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/4te2Q.png" alt="enter image description here" /></a></p>