Check out the TBC Macros Forum. We have written a TML that creates a Site Improvement Legend, that gives a color coded legend that describes the Site Improvements assigned to a Project and the layers that make up that SIte Improvement and the thicknesses of each layer. This is exactly what I think you are looking for. I posted a Video of the workflow the week before Christmas (or thereabouts). The TML is called Site Improvement Legend
Here is the Link
TML - Site Improvement Legend
Alan