Why useless? It's not that hard.
You can recalculate the polygon colors by taking the given vertice colors, adding all 3 colors from the polygon together and dividing them by 3. Then you have your poly color. Quite simple algorithm.
The edges can be recalculated, too, by going through all polygons and creating an edge array.
That's the way I handles those two parts in ultima...
- Alhexx