With Ms. Singer, Ms. Harris has favored simple fitted silhouettes but often lets color do the talking. Witness a sequined goldenrod Ralph Lauren halterneck dress worn to the Hollywood Foreign Press Association/InStyle cocktail party in November. “Every actress was at that event, and she really stood out, not because she was trying but because of that color, and because it flattered her figure — her arms! — without showing too much skin,” Ms. Singer said.

No last-minute triceps dips were needed for the visual statement made by a Gucci silver metallic tuxedo at the Hollywood Film Awards the same month. Ms. Singer said the outfit, with its sharp tailoring and lion embroidered on the back, was a nod to Hillary Clinton’s presidential campaign. “It was about women being empowered,” she said.

Though Ms. Harris knows her way around a pantsuit (see also a white Emanuel Ungaro option at Variety’s Women of Power Luncheon, and a white double-breasted Dolce & Gabbana number worn to the TimesTalks event for “Moonlight”), occasionally she likes to go retro. In the navy Carolina Herrera ball gown she wore (with Christian Louboutin flats) to the Governors Awards in November, she was having an Old Hollywood meets modern practicalities moment.

Less successful are her quirky moments. An orange Gucci minidress with a frilly black neckline that she wore at the British Independent Film Awards and a brown print Rodarte with papier-mâché-like white bust at the “Collateral Beauty” London premiere read costume-y on her lithe frame. Ms. Erlanger’s choice for the “Collateral Beauty” New York premiere was more on point: a neon floral Rosie Assoulin dress that ended above the ankle with Dick Tracy-yellow pumps. Sure it was December, but what’s a little pantyhose-less chill when an awards-season campaign is at stake?

More unexpected picks with Ms. Erlanger included an offbeat (perhaps dated?) Stella McCartney strapless black bodice with sheer skirt design for the Critics’ Choice Awards last month, and a winning gold sequined tunic and pants by Monse at the Gotham Independent Film Awards in November.