diff --git a/doc/api_assets/style.css b/doc/api_assets/style.css
index 4bff9e3299f25f..43d7994e287c3e 100644
--- a/doc/api_assets/style.css
+++ b/doc/api_assets/style.css
@@ -4,7 +4,7 @@
   --black1: #090c15;
   --black2: #2c3437;
   --black3: #0d111d;
-  --blue1: #00f;
+  --blue1: #0a56b2;
   --white: #ffffff;
   --white-smoke: #f2f2f2;
   --grey-smoke: #e9edf0;