Honestly from the standpoint of personal preference I say go with what you want. If you do that you will be much happier in the dress. If you are going for accuracy as a HUGE Aurora fan I can offer you some stats.
Cinderella's dress is silver in the movie to be accurate, however, they decided to make her dress light blue for merchandising purposes. This became an issue for Aurora when she came along in her royal and perriwinkle blue dress. The offical reason Aurora is merchandised in pink is due to the fact the book closes, at the end of the movie, with her in pink. Don't understand the logic in that for reasons I won't get into. The truth of the matter is they just want to keep the two blonde girls seperate and they feel pink will market better. The facts are Aurora spends 27minutes 48 seconds in the blue dress versus the 18 seconds she wears the pink version. (yes i will admit I am that obsessed
) Also Flora doesn't even realize Aurora has spent the entire movie in the blue dress till the end when the princess is dancing. Merriweather takes 6 seconds to notice.
Also they made a blue dress for the Aurora in the Maleficent movie. No pink version in that movie so someone knows the truth.
Like I said, just pick your favorite color nad have a blast in it. Aurora is an amazing character and I love finding people who love my fave Disney Princess.