diff --git a/src/Graphic3d/Graphic3d_ArrayOfPrimitives.hxx b/src/Graphic3d/Graphic3d_ArrayOfPrimitives.hxx
index 9d78df553c..fb4c72aa29 100644
--- a/src/Graphic3d/Graphic3d_ArrayOfPrimitives.hxx
+++ b/src/Graphic3d/Graphic3d_ArrayOfPrimitives.hxx
@@ -344,10 +344,11 @@ public:
 
     if (myVCol != 0)
     {
-      Graphic3d_Vec4ub aColor (Standard_Byte(theR * 255.0),
-                               Standard_Byte(theG * 255.0),
-                               Standard_Byte(theB * 255.0), 255);
-      SetVertexColor (theIndex, *reinterpret_cast<Standard_Integer*>(&aColor));
+      Graphic3d_Vec4ub *aColorPtr = 
+        reinterpret_cast<Graphic3d_Vec4ub* >(myAttribs->changeValue (theIndex - 1) + size_t(myVCol));
+      aColorPtr->SetValues (Standard_Byte(theR * 255.0),
+                            Standard_Byte(theG * 255.0),
+                            Standard_Byte(theB * 255.0), 255);
     }
     myAttribs->NbElements = Max (theIndex, myAttribs->NbElements);
   }
@@ -356,7 +357,23 @@ public:
   void SetVertexColor (const Standard_Integer  theIndex,
                        const Graphic3d_Vec4ub& theColor)
   {
-    SetVertexColor (theIndex, *reinterpret_cast<const Standard_Integer*> (&theColor));
+    if (myAttribs.IsNull())
+    {
+      return;
+    }
+    else if (theIndex < 1
+          || theIndex > myMaxVertexs)
+    {
+      throw Standard_OutOfRange ("BAD VERTEX index");
+    }
+
+    if (myVCol != 0)
+    {
+      Graphic3d_Vec4ub *aColorPtr = 
+        reinterpret_cast<Graphic3d_Vec4ub* >(myAttribs->changeValue (theIndex - 1) + size_t(myVCol));
+      (*aColorPtr) = theColor;
+    }
+    myAttribs->NbElements = Max (theIndex, myAttribs->NbElements);
   }
 
   //! Change the vertex color of rank theIndex> in the array.
diff --git a/src/ViewerTest/ViewerTest_ObjectCommands.cxx b/src/ViewerTest/ViewerTest_ObjectCommands.cxx
index 75950fd831..ec3565cf2f 100644
--- a/src/ViewerTest/ViewerTest_ObjectCommands.cxx
+++ b/src/ViewerTest/ViewerTest_ObjectCommands.cxx
@@ -2960,7 +2960,7 @@ static int VDrawSphere (Draw_Interpretor& /*di*/, Standard_Integer argc, const c
   Handle(TColStd_HArray1OfInteger) aColorArray = new TColStd_HArray1OfInteger (1, aNumberPoints);
   for (Standard_Integer aNodeId = 1; aNodeId <= aNumberPoints; ++aNodeId)
   {
-    aColorArray->SetValue (aNodeId, *reinterpret_cast<const Standard_Integer*> (&aColor));
+    aColorArray->SetValue (aNodeId, *reinterpret_cast<const Standard_Integer*> (aColor.GetData()));
   }
   aShape->SetColors (aColorArray);