We used white rose petals, because I heard that red rose petals can possibly stain your dress. I also avoided bubbles for the exact same reason you mentioned....I was a bridesmaid in a wedding that used bubbles and the bubbles RUINED my bridesmaid dress (they also stained the bride's gown). My bridesmaid dress was hunter green and after the bubbles attacked it, I had huge discoloration marks all over it (to this day).