This may not be the best option as I would assume only professional whitening would be best but from what i have researched online you should not whiten your teeth with braces on...but the following works well for me!
I use Crest Whitening Toothpaste with baking soda which i brush with 3 times a day. Usually after anything that is dark that could stain my ceramics (like juice or sauces). Try brushing directly after anything staining so that it wont set in...I am in love with Crest Whitening rinse too!!! I use the rinse twice a day...it tastes exactly like hydrogen peroxide and its kind of gross but well worth it in my opinion.
My dentist and Ortho always say how white my teeth are and the only explanation i have is the brands of toothpaste and rinses I use and maybe the fact that I donâ€™t drink coffee or dark beverages.
I am not a coffe/tea/coke/pepsi drinker and this may be unrealistic but try drinking dark things through a straw so that it does not stain your braces and teeth. It may sound crazy to drink hot coffee through a straw but maybe do this a week or two before your wedding to prevent further staining. I heard about this from a magazineâ€¦they said this is why you always see celebrities drinking through straws (it prevents teeth staining. maybe a weird myth but it makes sense). I drink hot chocolate a lot in the winter and since getting my braces I always use a straw...may seem weird but it helps.
So that is my 2 cents if itâ€™s worth anything