Yes the dress was created yellow for a specific reason. Actually it is more gold than yellow and the color was chosen for promise and the future of happiness.
A bird costume would be easy, and lots of birds are yellow.
If you want the real deal, go to the source and get a branded Disney costume from their store. But for a look-alike style try www.orientaltrading.com/Belle
One way is finding the costume online. You can also go to your local party store, and they may have a similar dress as Belle in the store. After all, she is from a famous Disney movie.
use yellow fabric, and make a sleevless layered gown, the go sew it at your best friends's house with your other friend Halloween night. ;)
Yellow
You can visit the website www.ccreativedesigns.com, and you can find many belle custome designs including the Beauty and the Beast, sleeping beauty and other belle designs.
Simplicity Costume's Pattern 9902 Disney Princess Belle & Ariel is sold directly from Simplicity and from Etsy, eBay, iOffer, Pattern Kingdom, and Dawn's Pattern Shop.
yellow
The cast of Yellow Belle - 1998 includes: Bruce Adel as Hunt Burns Chandra lee Schwartz as Becky Hightower
The Flash
Belle is from Beauty and the Beast and is the princess with the brown hair, brown eyes, and yellow ball gown.
Costume jewelry has never been made of gold, thats why its called COSTUME