The problem costume solves
The double role at the heart of all three versions gives the audience a specific cognitive task: to know, at every moment, whether they are watching the criminal Don or the look-alike Vijay who replaces him. The face is the same. Costume is the primary tool that keeps the two men distinct.
In the 1978 original, directed by Chandra Barot, the distinction works through fabric and finish. Don moves in dark, fitted clothing — the wardrobe of a man accustomed to being obeyed. Vijay, a street performer, dresses loosely and cheaply. When Vijay is pressed into impersonating Don, he inherits Don's clothes, and the visual grammar is instantly altered: the same body reads as dangerous because the costume says so. The audience is held inside an irony the other characters cannot see.
Farhan Akhtar's 2006 remake intensifies this. The production palette is cooler and harder — Southeast Asian city locations, sleek interiors — and the costumes follow. Don is dressed in tailored European cuts, often in dark neutrals that flatten against designed backgrounds. Vijay, in the brief passages where we see him before the switch, is visibly softer in colour and silhouette. The contrast is sharpened enough that even where the narrative depends on other characters failing to notice the difference, the audience is not confused.
There is also a chronological signal. Each version uses timeline placement to help the audience orient: scenes early in the story establish the men separately before they overlap, so costume difference can anchor what the narrative has already spelled out. When Vijay appears in Don's clothes in the second act, it reads as transformation rather than confusion.
The 2011 continuation, Don 2, does less work here — by that point there is no Vijay, and the doubling is gone — but the established costuming logic carries over: Don's wardrobe remains an armour of authority, signalling hierarchy to allies and enemies alike without a word spoken.