For much of it I would advocate using resin, 2 part epoxy, and a dremel.
Basically I'm suggesting you do thin layers, then use the dremel with an engraving bit to refine the forming work.
Believe it or not I think this is a good choice for a first project in 3d. I love taking on stuff I have no idea how to do.
The reason I'm suggesting you do layers over casting the whole thing is that doing a detailed mold for resins and plastics is even MORE difficult.
Oh, and you can tint fiberglas resin (just the resin mind you, not the stuff with fibers in it, most auto body shops carry it).
Take a look at the following website for ideas for what you can use as a colorant for the resin:http://glassattic.com/polymer/other_materials.htm