What do you suggest for transitional months where it might still be hot outside?
For the specific months of early fall, I think blended tones that bring together warm and cool elements are best. Colors like gray-greens, muted mauves, plummy purples, dusty blues, and rich teals are great during this season.
Classic blues and neutral shades are well-suited for nearly any season, so they are always good choices for those transitional times. I especially love metallic neutrals – silver, gold, bronze, rose gold – they look good year-round. Just take into account that the gown is the right silhouette, sleeve length, and the fabric is appropriate for the weather.