customizing mesh selection & highlight styles

Hello forum,
a quick question about mesh selection and highlight styles.
Please, have a look to the attached picture:

The surface mesh of a model is shown in wireframe mode.
When clicking a triangle is selected and shown using a "shrink" view, in gray
When moving the mouse each detected triangle is shown with a solid color

Is someone of you able to customize such styles?

Example: I would like to show the "selected" elements in solid green,
and the "detected" elements with the same color.

In order to activate selection I used:

aMesh->AddBuilder(aBuilder,true);

with flag "true". The I tried to add a customized MeshVS_Drawer to the builder,
but without success.

Thanks in advance!
Giovanni