Symphyandra - Campanula-like plants of not high rank, S. pendula from the rocky parts of the Caucasus, having branched pendulous stems and large cream-colored bell flowers, almost hidden in the leaves.
You could go with an innocent, small bouquet of cream-colored roses, for example, or go all out with many different shades of chrysanthemums.
If your dress is ivory (beautiful for October weddings!), a bouquet of cream-colored flowers may blend right in, especially in pictures.
One option is to use turquoise as the main frosting color and ask the decorator to make all of the accents white or cream-colored.
In gardens, on peaty soil and fine sandy loams, it spreads out into compact tufts covered with cream-colored and yellow flowers.