Item3D / mesh : restore original effect after it has been altered?

[billouparis]

Hello I have this Item3D i want to be able to dynamically change its effect. First I want to display the standard effect already coded inside the mesh file itself. After a certain time/action I want to update the effect to something I would set up. Then after another period of time I want to come back to the original effect described in the mesh file:
@
Item3D {
id: my3DItem
mesh: "blahblah";
}

onSomeEvent1 {
my3DItem.effect = Effect { color: "red"}
}

onSomeEvent2 {
// here I want my mesh to restore its original effect/ clear the red color on it
//what do I have to write here?
}

@

Thank you,
Bill