Appearance

"Power is beauty, and I've got the power!"

Here I'll give you some detailed descriptions and speculations on Flea's design and wardrobe.

Colours

Flea's costume is dominated by pink, red, white and brown colours, matching his hair and eyes. While Flea has fair skin on Toriyama's official character illustration, the in-game sprite is pink coloured. I really have no proper explanation for the color mismatch. The in-game colors make a lot more sense, though. If Flea was Caucasian skinned like in Toriyama's design, he would have been the only one of the team (if not if of all the Mystics) with a non-mystic skin colour. You will notice that the Mystics cover almost all colours of the rainbow, except for regular human flesh tones.
The pink/red tones fit well to his girlish style and it's obviously a direct opposite to the cold and serious blue-skinned Slash.

Wardrobe

Flea wears a white heart-shaped top. This is not Flea's Vest/Bustier, because that one is obviously worn under the shirt.
He wears a broad leather belt around his waist. The buckle is round shaped and golden. There are some additional buckles on both sites to tie up additional accessories such as the tiny golden tea pod.
The tea pod reminds of a genie bottle known from the Arabian nights tales. I presume it is used for summoning spells or smelly stuff to drug people ;).
He wears a red mini-skirt over tight brown pants. The shoes are black with yellow plating. They remind a bit on shoes from the 19th century. The gloves are white and have open fingertips (maybe it's more easy to cast spells this way…) Let's not forget the long white cape with dark interior and a straight red ribbon at the bottom.
Flea also wears earings - a shiny round red gem on each ear.

Tiny differences

The in-game Flea wears a white skirt without pants. The hair-ribbon is blue instead of white/silver. And as mentioned above, the skin is pink instead of 'white'.