Forum:Proton torpedo questions

I have a couple of questions concerning proton torpedos. I recently started reading the X-Wing series and i just finished The Krytos Trap and because i do not currently have the next book in the series i decided to look back reflect. Throughout The Krytos Trap and i believe the first book in the series whenever a proton torpedo was fired it was blue and similar to an ion cannon shot. Also the proton torpedos hit shields and exploded outside of the shield. I dont know if I've been playing to much Empire at War (which is a very fun game i must add) but i was under the impression that not only were proton torpedos red in color (which were also the color of the proton torpedos fired by Luke Skywalker on the first death star) but that they were objects that could pass through shields because unlike laser bolts that were made up of pure energy i thought they had mass which would allow them to pass through shields. Now maybe i just overlooked something simple while reading the page or maybe im just completely overthinking this but it would be nice to get someone elses opinion on this. Thanks -MATT