Before I get my head bitten off for the "inaccuracy", I made this costume LONG before the movie became a reality. I know that I don't look anything like the actress portraying her, but I still enjoyed pretending to be Bella for the booksigning. :)
I based the design off of the photo of the dress that Stephenie Meyer had posted on her website of what she pictured Bella's prom dress to look like. I think she still has it up on her site. You can go take a peek if you'd like: www.stepheniemeyer.com.
Finding fabric came next, and my good friend (who was going to be making a Victoria costume) and I searched several different fabric stores for the right color fabric. Sure, it's not hyacinth colored like described, but the color DID compliment the floral taffta that we used for the outer layer of the dress.
Overall, as amaturely put together as it is, I'm extremely happy with the outcome. Many happy memories were made while wearing the dress, including meeting Stephenie Meyer for the first time. :)
Best Bella Swan Impersonation - Awarded by Stephenie Meyer (May 5th, 2007) at her New Moon booksigning.