Step writting and set color

Hi, I have got an issue with STEP writer,

I have updated my Opencascade version and color are not exported.

On version 6.7.1 everything works well

but with version 6.8.0 and 6.9.3 the color writing don't work.

I search on release note for a regression or a bug but i don't find anything... Am I missing something ?

Here is my code snippet :

.cpp :

// Application and document creation
myApp_ = XCAFApp_Application::GetApplication();
myApp_->NewDocument( "MDTV-XCAF", aDoc_);

if ( !XCAFDoc_DocumentTool::IsXCAFDocument (aDoc_) )
    return -1;

// Tools
myAssembly_ = XCAFDoc_DocumentTool::ShapeTool( aDoc_->Main() );
myColors_   = XCAFDoc_DocumentTool::ColorTool( aDoc_->Main() );
myLayers_   = XCAFDoc_DocumentTool::LayerTool( aDoc_->Main() );

//-----------------------------------------------------
// STEP Content

{
    BRep_Builder builder;

    // Builder
    TopoDS_Compound comp;
    builder.MakeCompound(comp);

    std::vector<TopoDS_Shape> subshapevec;
    std::vector<CBPoint> colvec;
    std::vector<std::string> namevec;
    
    // Retrieve shape informations
    TopoDS_Shape shape = ...;
    // RGB between 0 and 255
    CBPoint couleur = ...;
    
    // Browse topods_shape
    TopExp_Explorer expSolid;
    for ( expSolid.Init( shape, TopAbs_SOLID, TopAbs_COMPSOLID); expSolid.More(); expSolid.Next())
    {
        builder.Add( comp, expSolid.Current());
        subshapevec.push_back(expSolid.Current());
        colvec.push_back(couleur);
        namevec.push_back(...);
    }
    
    // Label creation
    TDF_Label lComp = myAssembly_->AddShape( comp, true);
    TCollection_ExtendedString aName(...);
    TDataStd_Name::Set (lComp, aName);
    
    // Ajout des elements.
    for (int i = 0; i < (int) subshapevec.size(); i++)
    {
        // SubShape
        TopAbs_ShapeEnum type = subshapevec[i].ShapeType();
        TDF_Label lFils = myAssembly_->AddSubShape (lComp, subshapevec[i]);

        // Names
        TCollection_ExtendedString bName(namevec[i]);
        TDataStd_Name::Set (lFils, bName);

        // Colors
        Quantity_Color couleur (
            ((double) colvec[i].x) / 255.,
            ((double) colvec[i].y) / 255.,
            ((double) colvec[i].z) / 255.,
            Quantity_TOC_RGB);
            
        myColors_->SetColor(lFils, couleur, XCAFDoc_ColorGen);

        // Also try this
        //myColors_->SetColor(subshapevec[i], couleur, XCAFDoc_ColorGen);

        subshapevec[i].Nullify();
    }
}

//-----------------------------------------------------
// Step writer

STEPControl_StepModelType mode = STEPControl_AsIs;
STEPCAFControl_Writer writer;

writer.SetColorMode(Standard_True);

if ( ! writer.Transfer ( aDoc_, mode ) )
    return -1;
else
    IFSelect_ReturnStatus stat = writer.Write( fileName );

myApp_->Close(aDoc_);

return 1;

.h :

    Handle(XCAFApp_Application) myApp_;
    Handle(TDocStd_Document)    aDoc_;
    Handle(XCAFDoc_ShapeTool)   myAssembly_;
    Handle(XCAFDoc_ColorTool)   myColors_;
    Handle(XCAFDoc_LayerTool)   myLayers_;