fix(examples): remove backgroundColor for dark mode
diff --git a/public/examples/ts/bar-polar-label-radial.ts b/public/examples/ts/bar-polar-label-radial.ts
index c42a96e..fe04671 100644
--- a/public/examples/ts/bar-polar-label-radial.ts
+++ b/public/examples/ts/bar-polar-label-radial.ts
@@ -33,7 +33,6 @@
       formatter: '{b}: {c}'
     }
   },
-  backgroundColor: '#fff',
   animation: false
 };
 
diff --git a/public/examples/ts/sankey-itemstyle.ts b/public/examples/ts/sankey-itemstyle.ts
index 2290737..09bf165 100644
--- a/public/examples/ts/sankey-itemstyle.ts
+++ b/public/examples/ts/sankey-itemstyle.ts
@@ -10,7 +10,6 @@
     subtext: 'Data From lisachristina1234 on GitHub',
     left: 'center'
   },
-  backgroundColor: '#FFFFFF',
   series: [
     {
       type: 'sankey',