marine dress blues with white pants I see Marines both wear blue and for full uniforms. In which case they use which? : r/uniformporn Military Dress Uniforms by Branch:
Description
Casablanca Bridal 2551 A-Line Ballgown Cap Sleeves Plunging Neckline Lace Long Wedding gown

This one from Nancy Ganz includes hidden bonded panels that provide a little extra smoothing and support around the stomach and thighs
The dress is fashioned in a classic A-line style, which is universally flattering and never goes out of fashion

So to sum up these points, the reason that black suits are so ubiquitous in society today is largely as a result of various adjacent figures coming together on society as a whole

Its fucking blue