According to the internet...
- "Festival formal is slightly less formal than 'black tie,' but tuxedos or suits are appropriate for men, long or short dresses for women; sequins, glitter, and bright/flashy colors or patterns are encouraged. When it was all said and done, it really was a 'formal, anything goes' affair."
- "Festive attire is unique among other dress codes in that it heavily emphasizes the use of specific colors, patterns, and textiles to tap into the holiday vibe: Sequins, velvet, cashmere, jewel tones, tartan, corduroy, tweed... greens, golds, and lots of sparkles and glitter all fit the requirements of this fun dress code. .. This dress code can also signify cocktail attire with creative flair."
Please just be comfortable, and be ready to have fun!