diff --git a/chart-guide/standard-charts/heat-map-chart.md b/chart-guide/standard-charts/heat-map-chart.md
index c61514446..d589a7d5d 100644
--- a/chart-guide/standard-charts/heat-map-chart.md
+++ b/chart-guide/standard-charts/heat-map-chart.md
@@ -572,7 +572,8 @@ In a heat map chart, you can show multiple labels in different positions, starti
 
 Refer to the code below:
 
-```color: [
+```json
+color: [
       {
         code: "#ff9933",
         maxvalue: "-4",