The changes in Hamlet’s character are shown in his modifications in outfit. Initially, there is the Hamlet in the “nighted colour”, in mourning for his dad and resentful of his mother and uncle. This is Hamlet in Act one.
He is passive and reactive, making snarky remarks under his breath and behind the king’s back however being sullen and unresponsive in his presence. After the go to of the Ghost, Hamlet changes.
Ophelia describes his costume as “his doublet all unbraced, no hat upon his head, his stockings fouled and down-gyved to his ankle. This is Hamlet of the antic personality. His pretense of madness provides him the liberty to hone his wit on the various spies which pertain to sound him out. He becomes more active, scheduling and basically directing the play The Murder of Gonzago, but he is a perfectionist, and can not see his method to eliminating Claudius without the situations being just right. He thinks he has got them right however he is wrong– it’s Polonius behind the arras and not Claudius.
Then he is sent out to England. He finds that Claudius is not going to await the best chance, however has currently made plans to have Hamlet killed. He changes again. He schedules the deaths of Rosencrantz and Guildenstern, and when the pirates attack, he takes the opportunity to board their ship, and bribes them to go back to Denmark. He gets here on the coasts “naked and … alone”. “Naked” here means that he has only the clothes he stands up in, whatever he can find.
Hamlet is now an opportunist. He no longer firmly insists that the conditions be perfect. He will take his chance where he discovers it. He becomes a fatalist: “There is an unique providence in the fall of a sparrow … the readiness is all.” It is when he reaches this stage in his journey that he can do what he wishes to do and needs to do. He expresses his love for Ophelia (far too late) and is able to take his vengeance on Claudius (practically far too late).