diff --git a/core/src/main/resources/org/apache/spark/ui/static/spark-dag-viz.css b/core/src/main/resources/org/apache/spark/ui/static/spark-dag-viz.css
index 1fbc90b832bc..e44a724c202f 100644
--- a/core/src/main/resources/org/apache/spark/ui/static/spark-dag-viz.css
+++ b/core/src/main/resources/org/apache/spark/ui/static/spark-dag-viz.css
@@ -22,6 +22,7 @@
 #dag-viz-graph .label {
   font-weight: normal;
   text-shadow: none;
+  color: #333;
 }
 
 #dag-viz-graph svg path {
diff --git a/sql/core/src/main/resources/org/apache/spark/sql/execution/ui/static/spark-sql-viz.css b/sql/core/src/main/resources/org/apache/spark/sql/execution/ui/static/spark-sql-viz.css
index 6ba79dc74718..a40ae41bf5a5 100644
--- a/sql/core/src/main/resources/org/apache/spark/sql/execution/ui/static/spark-sql-viz.css
+++ b/sql/core/src/main/resources/org/apache/spark/sql/execution/ui/static/spark-sql-viz.css
@@ -19,7 +19,7 @@
   font-size: 0.85rem;
   font-weight: normal;
   text-shadow: none;
-  color: black;
+  color: #333;
 }
 
 #plan-viz-graph svg g.cluster rect {