diff --git a/interface.go b/interface.go
index 479c3aff2ba0d8e773cfa01d74de8d96b51e94f4..ab642cee4ac2b14887f11f62a4a7e011c43de3e4 100644
--- a/interface.go
+++ b/interface.go
@@ -72,7 +72,7 @@ type TrianglesPosition interface {
 // Default value for a color is the white color.
 type TrianglesColor interface {
 	Triangles
-	Color(i int) color.Color
+	Color(i int) NRGBA
 }
 
 // TrianglesTexture specifies Triangles with Texture propery.