Cheongdam-dong is Apgujeong's slightly-more-serious neighbor. The salons are higher-end, the cafés have less seating because they don't want random people sitting through a single Americano for three hours, and the outfits trend slightly more serious too. Less silk, more cashmere. Less shine, more drape.
I get my hair done at a place near Cheongdam Station maybe twice a year — it's a splurge, my friend Hana introduced me to the stylist, and I always end up sitting in the chair for four hours. The outfit I default to for these days is entirely beige and cream, head to toe, because (a) anything dyed dark would risk transferring color to wet hair and (b) an all-tonal outfit gives the hair the visual stage, which is what you've paid for.
The trick to all-beige is varying the depth of the tone. Cream sweater + warmer beige pant + honey-toned bag = looks intentional. Three identical beiges = looks like a uniform.