9 of the best and worst looks from the 'Bridgerton' season 4 world premiere

Ha, who stars as Sophie Baek in season four of "Bridgerton," arrived at the premiere in an ice-blue gown designed by Prada.

The dress had a bedazzled halter neckline that matched the beading on a cutout on the bodice. The floor-length skirt featured two large pleats that cascaded into a train that trailed behind Ha as she walked the red carpet. Sparkly jewelry completed Ha's glamorous look.

The ensemble looked like a modern take on Cinderella's iconic blue dress. It was fitting since Julia Quinn's "An Offer from a Gentleman," upon which season four is based, is a retelling of "Cinderella."

As he stepped into the leading role of "Bridgerton," Thompson wore an all-black ensemble. He paired a black suit with a black button-down shirt, a black tie, and a black flower on his lapel. The only color on the look was a sparkly tie clip.

The look was stylish, but the black pieces blended so well that it became difficult to distinguish the different elements, particularly the flower and pin.

Some pops of color may have made the outfit stand out more.

Jessie, who plays Eloise Bridgerton, chose an oversize suit for the event.

The double-breasted jacket and pants were black, but they were adorned with an assortment of flowers in various colors to give the suit some pop. Jessie paired the suit with a slicked-back hairstyle and several earrings and rings, adding a high-fashion edge.

Rosheuvel, who plays Queen Charlotte, wore a floor-length sweater dress from Sonney for the premiere. The burnt orange look had a slight sparkle and a cowl neckline, and Rosheuvel wore a matching coat and color-coordinated earrings.

The outfit was stylish, but it didn't feel formal enough for the red-carpet event. It may have worked better for a daytime press event, or Rosheuvel could have chosen a dress with the same silhouette in a different fabric.

Alli, who plays Lord John Stirling on "Bridgerton," wore an oversize black suit to the event.

He paired the suit with a white shirt, which he wore without a tie, and it peeked out from the cuffs of his jacket. He added a small silver brooch to his lapel for a chic addition.

The modern take on a tuxedo exuded high fashion.

Dodd, who married John Stirling as Francesca Bridgerton in season three of "Bridgerton," chose a black Giambattista Valli Paris set for the premiere.

The top was a black, cropped shrug with a V-neck and a button closure that revealed her midriff. It was paired with a low-waisted, calf-length skirt that poofed out around her, giving it a ball-gown feel despite the modern silhouette.

Black heels and silver jewelry tied Dodd's stylish look together.

The Lady Danbury actor's custom Torlowei gown for the premiere was beautiful, with a high neckline and black lace detailing.

However, Andoh's open-toed black shoes didn't quite match the dress, as they seemed less formal than the gown. Different shoes and statement earrings could have better accented the ensemble.

Leung, who will make her debut on "Bridgerton" as Lady Araminta Gun, walked the red carpet in a black Toni Maticevski dress.

Its strapless, scooped neckline formed points for a touch of drama before flowing into a corset bodice. The skirt was structured, poofing out around her waist in a dramatic ball-gown shape before flowing back into a pencil skirt. The center of the dress was made of ribbed fabric, adding dimension.

Chopard jewelry and strappy Christian Louboutin heels completed the look. Between the classic detailing, modern flair, and dark color, the dress was the perfect red-carpet companion for the wicked stepmother role Leung will play on the show.

Rhimes looked every bit the queen of the ton in the silver gown she wore to the premiere, which was styled by Dana Asher Levine.

The strapless gown had a slight point in the center of the straight neckline, and it cinched at Rhimes' waist with a belt. The entire gown was covered in silver and bronze sequins arranged in vertical strips, shimmering as Rhimes walked.

The pièce de résistance was a cape that coordinated with the gown. It sat on Rhimes' shoulder and flowed to the floor, giving the look a regal edge that was more than fitting for the occasion.