Unlike Dante who pretty much remains the same appearance wise apart from his clothing, Vergil was one of the characters who went through a few design changes during the development of the Devil May Cry series.
In earlier designs, Vergil was originally seen to have long hair and to weild a rapier, but was scrapped for the slicked back look which is maintained in current designs. Although the Nelo Angelo's casual attire seen in the third game wasn't shown in the first because he is always seen wearing amour,
it was one of the potential designs for Vergil in the first game. Also note that Sparda's human form similar to Nelo Angelo's human form in the third game, but in the first game his human design is completely different.
± In General One of the main points in the overall design of Vergil is to make him "simple and easy to perceive". Because of the shortness of the Devil May Cry 3 game, and the complexity of his character, they used his design to simply promote the fact that he and his brother are seen as opposites. In general, Vergil's overall style is more sophisticated than his brother.
The most notable feature is his blue coat which is meant to contrast that of Dante's. Vergil's coat is long in length, to the point that it barely touches the ground.
At the base of the coat, it is cut in three sections to enable easy movement. In his coat is a orange colored floral brocade. On the coat is a continuous embroided vine motif which goes from Vergil's left breast, around his neck, and down to his right knee.
Compared to Dante's coat, Vergil's coat uses buttons instead of zippers and buckles. The front buttons are the kinds that are attached through holes, which Vergil has left undone. There is also what seems to look like snap buttons, one for each strap on his sleeves.
Under the coat, Vergil wears a dark colored vest and pants. Tucked in his vest infront of his throat is a dark colored cravat which is blue in CG design materials. He also wears brown boots that go up to his knees, and directly below the knees the boots have two strapped belts.
In addition, Vergil wears dark beige open finger gloves which only cover the palm of his hands.
In Devil May Cry 3: Special Edition, Vergil is a playable character. Like Dante, he also has a selection of costumes to choose from. One of Dante's costume is of him shirtless, as seen in the first mission of the game. In Note of Naught, it mentions that they also wanted something similar with Vergil. However, in fear of evoking massive nose bleeds for female fans, they settled with without his coat wearing a sleeveless top. Something which they thought to be as being "more Vergil-like".
± Nelo Angelo In Vergil's design as Nelo Angelo in the first game, he looks reminiscent of Sparda in his demon form. In the game, Nelo Angelo is always seen wearing a dark colored full body amour which seems to "clank" whenever he moves. On his back, there is a purple colored cape with an image of a vine in the center.
In Devil May Cry 3: Special Edition, Nelo Angelo is a playable form of Vergil. The devil trigger is essentially his armored form, but in human form he looks almost identical to Sparda. Like his father, Nelo Angelo wears a purple suit which has yellow edges instead of red. In the chest area there is something that looks like a lace trim collar with a skull figure near the base that has a blue jewel embedded. Nelo Angelo still wear the amulet his mother gave him, which is shown above the lace trim collar and a white shirt. In addition, he wears dark colored dress shoes which have a light colored ornament on it. Overall, Nelo Angelo looks rather stylishly debonair. Almost as if he was like royalty in the demon world.
Something to nose is the facial features. In human form as Nelo Angelo, Vergil's body has become pale. His eyes become red, and there are light grey blue markings all over his face. As mentioned in the design archives of Note of Naught, the face markings were randomly put in for fun as a cross reference to Nelo Angelo's helmet. It doesn't mean anything at all.
± The Vine Motif As you may have already noticed the vine on Vergil's blue coat, and the vine like symbol on Nelo Angelo's cape, the vine motif is something to note of when it comes to Vergil and Nelo Angelo's design,
Symbolistically vines signify intoxication and strong desires, which is similar to how Vergil is "lost" by evil and craves power. The fact that the vines have thorns also adds more to the meaning. Although not a vine, thorns on rosebushes symbolize contrast, like the way which Vergil and Dante are seen as opposites.
± Other things to notice... Dante and Vergil can also be considered to be albino because they have white hair, light blue eyes, and pale skin. Perhaps it is because of their half demon and half human heritage?
Unlike Dante who pretty much remains the same appearance wise apart from his clothing, Vergil was one of the characters who went through a few design changes during the development of the Devil May Cry series.
In earlier designs, Vergil was originally seen to have long hair and to weild a rapier, but was scrapped for the slicked back look which is maintained in current designs. Although the Nelo Angelo's casual attire seen in the third game wasn't shown in the first because he is always seen wearing amour,
it was one of the potential designs for Vergil in the first game. Also note that Sparda's human form similar to Nelo Angelo's human form in the third game, but in the first game his human design is completely different.
One of the main points in the overall design of Vergil is to make him "simple and easy to perceive". Because of the shortness of the Devil May Cry 3 game, and the complexity of his character, they used his design to simply promote the fact that he and his brother are seen as opposites. In general, Vergil's overall style is more sophisticated than his brother.
The most notable feature is his blue coat which is meant to contrast that of Dante's. Vergil's coat is long in length, to the point that it barely touches the ground.
At the base of the coat, it is cut in three sections to enable easy movement. In his coat is a orange colored floral brocade. On the coat is a continuous embroided vine motif which goes from Vergil's left breast, around his neck, and down to his right knee.
Compared to Dante's coat, Vergil's coat uses buttons instead of zippers and buckles. The front buttons are the kinds that are attached through holes, which Vergil has left undone. There is also what seems to look like snap buttons, one for each strap on his sleeves.
In Devil May Cry 3: Special Edition, Vergil is a playable character. Like Dante, he also has a selection of costumes to choose from. One of Dante's costume is of him shirtless, as seen in the first mission of the game. In Note of Naught, it mentions that they also wanted something similar with Vergil. However, in fear of evoking massive nose bleeds for female fans, they settled with without his coat wearing a sleeveless top. Something which they thought to be as being "more Vergil-like". 
In Vergil's design as Nelo Angelo in the first game, he looks reminiscent of Sparda in his demon form. In the game, Nelo Angelo is always seen wearing a dark colored full body amour which seems to "clank" whenever he moves. On his back, there is a purple colored cape with an image of a vine in the center.
In Devil May Cry 3: Special Edition, Nelo Angelo is a playable form of Vergil. The devil trigger is essentially his armored form, but in human form he looks almost identical to Sparda. Like his father, Nelo Angelo wears a purple suit which has yellow edges instead of red. In the chest area there is something that looks like a lace trim collar with a skull figure near the base that has a blue jewel embedded. Nelo Angelo still wear the amulet his mother gave him, which is shown above the lace trim collar and a white shirt. In addition, he wears dark colored dress shoes which have a light colored ornament on it. Overall, Nelo Angelo looks rather stylishly debonair. Almost as if he was like royalty in the demon world.