diff --git a/models/resources/workflow/graph/graph.go b/models/resources/workflow/graph/graph.go
index a2a2758..ed3a0c6 100644
--- a/models/resources/workflow/graph/graph.go
+++ b/models/resources/workflow/graph/graph.go
@@ -20,7 +20,7 @@ type GraphLink struct {
 }
 
 type GraphLinkStyle struct {
-	Color           int64    `bson:"color" json:"color" validate:"required"`
+	Color           string   `bson:"color" json:"color" validate:"required"`
 	Stroke          float64  `bson:"stroke" json:"stroke" validate:"required"`
 	Tension         float64  `bson:"tension" json:"tension"`
 	HeadRadius      float64  `bson:"head_radius" json:"head_radius"`