The suit mainly consisted of scarlet, crimson and yellow. It had a scarlet zip-up hooded vest with yellow lightning symbol on the sides with crimson in-between the lines and a yellow lightning bolt symbol on the back. It had a brown belt and silver buckle, crimson pants and scarlet and red running shoes. A long-sleeved crimson shirt under the vest, scarlet arm bands and red sports sun glasses. After a while, Bart seemingly dropped the sun glasses from his suit. It's unknown if the sun glasses were high tech, like the sun glasses that Oliver Queen used as part of his Green Arrow suit. Following Allen's apparent death, this suit was put on display in the JSA Brownstone.
Few months after Clark officially went public as Superman, Bart changed his whole look. He shaved his hair back to his short blond hair, in order to cut down drag, similar to what swimmers do in order to be more aerodynamic when he runs. He also changed his costume to a red sweatshirt with a white lightning bolt over his chest and torso and black sleeves along with black running pants, red, black and white high-tech running sneakers and red cuff around each wrist as well as a pair of red sports goggles with yellow lenses which also has an elastic band (to keep the shades from flying off as Bart drops out of super speed).
- Although it is the costume for Impulse, it more resembles the Flash Costume from the comics. However his new costume resemble more like the original Impulse look with hints of his previous costume, as well as elements of Jay Garrick's classic comic costume.
- As pointed out by Clark in Masquerade, the hoodie would fall off while super speed, yet this was never shown to happen to Bart. However Season 11 writer Bryan Q. Miller announced a change in his costume mainly because of this fact.
- The colors of the costume are red and yellow. These are Bart Allen's signature colors as well as the colors of the Flash's costume. The second costume is a combination of red, white, black and a little blue more resembling Bart Allen's original Impulse costume in the comics.
- This suit consist of simply a hoodie, shirt and jeans, making it the most basic costume of the ones's featured on Smallville.