Luke is wearing the white desert garb of a moisture farmer. The white gives away Luke as a good guy instantly , and the loose fitting fabric gives away his humble origins. This version of Luke is a wide eyed boy ready to take on the world, even if he is naive about what that means.
Fun fact about the Pants Luke wore:
They were off-the-shelf levi's-bleached with back pockets and label razored off.
Luke's Rebel Pilot outfit , he wears when taking down the Death Star. It's a red Jumpsuit with white vest.
Luke's Ceremonial Outfit, when he receives his medal for his bravery in the battle against the empire. I would love to do a gender swap version of this. I love his yellow jacket.
Empire Strikes Back
Luke's hoth outfit
Luke's dagobah and Bespin Outfit.
Return of the Jedi
Here’s Luke at his most confident, but also his closest to the Dark Side. The all black, almost militaristic costume is incredibly cool but also indicative of the Emperor and Imperial uniforms. This is a Luke that’s dangerously close to falling from the light due to the weight on his shoulders, but also a Luke that’s seasoned and focused. The Expanded Universe pretty much used this as Luke’s default look for many of the years after the films.
As a result, Luke’s dark costume from Return of the Jedi takes another step toward being Darth Vader. If you look at the material on the legs and arms, it’s pretty much exactly the same as that on Vader’s costume.
The Force Awakens
You’ll notice similarities, including the white tunic sleeve and the darker robes . We also see that the artificial skin around Luke’s cybernetic hand is gone, leaving the remainder of his duel on Bespin for all to see.
We also know that Luke will have an Obi-Wan style beard, which is really the biggest difference between his look in the newest film and his Jedi Master look in the EU.
Luke Skywalker wielded at least two lightsabers during the Galactic Civil War. The first was his father's former weapon, that was retrieved and given to him by Obi-Wan Kenobi. He wielded this weapon for three years before losing it, and the hand holding it, in a duel against Darth Vader on the cloud city on Bespin. After losing his father's lightsaber, Skywalker built himself a new weapon, with a green blade, that he used to rescue his friends from Jabba the Hutt and during his final duel with Darth Vader.