I don't know if you found a solution to your problem or not, but after reading the posts, I went to the local college and asked around about a program that would do what you're looking for. One professor suggested, depending on the amount of colour detail you're requiring, that a drafting program, like AutoCAD, might be appropriate. Now, while I know that AutoCAD is a trademarked program, there might be something similar that you can download from the net, on either a shareware, freeware or trial basis.
Just a suggestion.
