diff --git a/optuna_dashboard/ts/components/GraphIntermediateValues.tsx b/optuna_dashboard/ts/components/GraphIntermediateValues.tsx
index fc2be23e..2d86e464 100644
--- a/optuna_dashboard/ts/components/GraphIntermediateValues.tsx
+++ b/optuna_dashboard/ts/components/GraphIntermediateValues.tsx
@@ -98,7 +98,7 @@ const plotIntermediateValue = (
           ? "(infeasible)"
           : ""
       }`,
-      ...(!isFeasible && { line: { color: "#CCCCCC", dash: "dash" } }),
+      ...(!isFeasible && { line: { color: "#CCCCCC" } }),
     }
   })
   plotly.react(plotDomId, plotData, layout)