Selphie's everyday uniform is extremely simple, consisting of a very short yellow denim dress with a silver zipper at the front, right in the middle; the zipper's pull is shaped like a sea shell. The big silver buttons on the straps and the two large pockets in the back give the dress a very informal, practical look, almost like that of overalls (which is what she was initially supposed to be wearing). A common misconception among cosplayers and fans in general is that Selphie's baggy brown boots are high-heeled: people, they most certainly are not, and if they were, they would be terribly out of character. Either way, as for accessories, all Selphie wears is a very thin silver necklace and a blue strap wrapped around her left forearm in a random pattern.
Balamb Garden Student Uniform
This is the girls' version of what all Balamb Garden students and/or SeeD cadets are supposed to wear: apparently not on a regular basis, but, at least, on official missions, like the SeeD field exams. The uniform possesses a dark blue color scheme that can easily be mistaken for black in FMV pictures (however, official concept art makes it clear that it is supposed to be a dark shade of blue), and is composed of a jacket tied with a large yellow bow just below the neck, with the Balamb Garden logo placed on the arm section of the right sleeve, and a very short, around mid-thigh skirt. Girls are also required to wear long dark blue socks with plain darker shoes to match (no, no heels here, either). The blouse, if any, isn't visible.
Selphie and the others can be seen wearing this uniform to the SeeD graduation party the day they pass the field exam; however, it seems that they are not required to wear it on subsequent missions, where they are always in their normal wear instead. Out of all the sets of clothes Selphie wears throughout the game, this is undoubtly the most formal. It consists of a black jacket and skirt; in comparison with the student uniform, the yellow bow is replaced with a red tie and the skirt is significantly longer, but the socks and shoes remain pretty much the same. The jacket's shoulders are blue, and large white patterns are visible on each side of the tie. There are plenty of red and golden stripes everywhere for instance, around the end of the sleeves.
Trabia Garden Student Uniform
Although we never actually see Selphie in her Trabia Garden uniform on any occasion in the game, it can be assumed that she had to wear it for a significant part of her young life, so it seemed logical to say something about it
(since no one ever does). The Trabia uniform is exactly like Balamb's, except it's of a lighter, greyish color scheme and the bow is purple, rather than yellow; also, quite obviously, in this case it's the Trabia Garden logo that is placed on the right sleeve. On a curious note, I have found that displays of this uniform in-game make it look significantly lighter than its original concept art (as seen to your left), to the point of making it seem a greyish shade of light blue instead. If you are interested, here's a screenshot.
Since Kingdom Hearts aims at a very broad audience, Tetsuya Nomura has given all of his characters from Final Fantasy games a more innocent, child-friendly look. Selphie is no exception, and many changes were made to her normal wear from Final Fantasy VIII: the silver necklace and the dress's zipper are gone, the latter giving place to a large pocket instead. Her boots have been replaced with wooden sandals, the blue strap around her left wrist with a plain blue beads bracelet, and the nunchaku with a jump rope (which, I suppose, is the innofensive object that bears a closest resemblance to her original weapon). Selphie is only thirteen years old in this game, so her curves are pretty much gone, too, and her eyes are a lot larger.
Kingdom Hearts II
Selphie is back for the 2005 sequel to Kingdom Hearts, in which she makes small cameo appearances walking with Kairi, both girls wearing school uniforms
(whoo-hoo! Sexy yuri! ...Or not really.). Although she is supposedly only one year older, our Selphie seems to have grown breasts, her curves being significantly more prominent now and fitting the uniform perfectly. This simple set of clothes consists of a white, short-sleeved blouse, along with a short skirt and a tie that share a pattern in the same light shades of blue. The socks are long and dark blue, and the plain black shoes are hugely oversized, as is common in the Kingdom Hearts series. She now wears a bordeaux accessory where her blue beads bracelet used to be.