source engine ForceMaterial

void ForceMaterial ( Color color, IMaterial* material, bool useColor = true, bool forceMaterial = true )
{
    if ( useColor )
    {
        float temp[ 3 ] =
        {
            color.r (),
            color.g (),
            color.b ()
        };

        float alpha = color.a ();

        m_pRenderView->SetBlend ( alpha );
        m_pRenderView->SetColorModulation ( temp );
    }

    if ( forceMaterial )
        m_pModelRender->ForcedMaterialOverride ( material );
}