title: how to change folium/geojson color
body: <p>i wish make it different color in different layer,
  so use the style_function as i googled like below:</p>
  
  <pre><code>style1 = {'fillColor': '#228B22', 'lineColor': '#228B22'}
  style2 = {'fillColor': '#00FFFFFF', 'lineColor': '#00FFFFFF'}
  
  test1=gpd.read_file('file2.geojson')
  folium.GeoJson(test1,name='test1',style_function=lambda x:style).add_to(mainmap)
  
  test2=gpd.read_file('file1.geojson')
  folium.GeoJson(test2,name='test2', style_function=lambda x:style2).add_to(mainmap)
  </code></pre>
  
  <p>however,it does not work on the line, still the default blue.</p>