I love the idea of brown and ivory! Any pastel/soft colors go great with brown. I think the chair ties in gold may be a little off or too much for your color palette of brown, ivory and yellow(flowers). I think brown would be a great color for chair ties if you could get them in the color of the bridesmaids dresses! The sunflower on each chair would tie everything together, so great idea. The flower bouquet is great since, like you mentioned, they already have brown in them. The bridesmaid dresses are cute to boot!