if you create a datum curve for your graphics. you can then create a cut, to say .005 deep, do a use edge, picking your datum curve as the driver. this would be approx. how deep a lazer would cut the material. then change the surface color by doing a view, cosmetic, color & apperance, pick surface color. then pick the surfaces to change.
If you do it using curves you can also choose the section option when creating them. We do this quite often because we don't specify depth or keep it a constant on this type of thing. Just adjust the cross hatching in the section of curves to give it an appearance of shading and not actually affect the surface of the part.
Here is the best way to do that. Create a Formed Datum Curve with text. Then do a Feature>Create>Tweak>Offset, Select the surface you want cut, when in sketcher mode select Use Edge>Select Loop, and then select the text you want cut. Let me know if you have any problems.