Shade or sun? Is the soil wet or dry usually, and sandy, clay, or ordinary loamy? How wide and long are the beds? You'll need to give us this information to get suggestions that will work in your situation. Can you post or link to pictures of the area? Are the beds currently empty or are you working with some plants already there? I have some ideas popping into mind, but I want to know more before I post any suggestions.

Due to the color of the bride's dress, I think you'll want to avoid reds, pinks and oranges and use blue, white, etc. Sometimes a flower's color or tint varies with soil, and you don't want to clash. One thing to look at is variegated leaves. There are plants with yellow or white as part of the leaf color as well as blue-gray leaves that will add color and you won't have to worry so much about timing which varies some year to year according to weather.

Once we know more about your area, specific plants can be suggested. Another thought is to go to a good local nursery (not a big box store) and ask for suggestions. Also, walk around neighborhoods for about two weeks before and after June 11 this year to see what is blooming in your area that you like. (Most gardeners are happy to share knowledge, so if folks are outside, ask them what plants are called and take notes.) Besides planting this year, you'll probably want to budget for some annuals next year to fill in gaps and add additional color where needed.

Since the beginning of time ladies have been choosing June for weddings because that is the season of the first flush of all roses. I would choose as many roses as I could (disregarding color clashes nonsense) and try for thornless as well. Good Luck!