You could do an array of metallic shades, incorporating champagnes and golds with coppers and bronzes. They'll look lovely with your ivory dress and the brown dresses, as well as add a touch of elegant shimmer to what would otherwise be traditional fall tones. Your flowers could mix creams with soft shades of taupe, beige, and silver. Cafe au lait dahlias or chocolate roses would be lovely mixed with greens that resemble fall foliage. Antique hydrangea and succulents could offer some nice tones in this palette as well.

For a more romantic look you could try a cool, dusty rose/mauve tone with touches of aubergine here and there. I'm visioning stained lips, satin ribbons, lush roses and antique candle holders pulling the look together.