The following is an excerpt from the CD insert booklet included in the New Mobile Suit Report Gundam W: OPERATION 1 Soundtrack KICA-251 which came out in 1995 by King Records. The booklet contains character profiles and small notes about them. Trowa's information is on page 10.
Trowa Barton
Status/Affiliation: MS Gundam Heavyarms Pilot
Age: Unknown (estimated 15 years old)
Ethnicity: Unknown
Gender: Male
Birthplace: Unknown (estimated L3 Colony Group)
Relations: Unknown
Height: 160 cm
Weight: 44 kg
Hair Color: Brown
Eye Color: Dark Green
Characteristics: Serves as a clown in the circus troupe.
Abilities/Special Skills: Recognizes himself as a weapon created to fight, excelling in taking action.
Personality: Cool and quiet. His actions occasionally reveal the sadness of one forced to live among people who fight.
The idea of a clown costume was thought to be unsuitable for such a handsome person, so he appears in the outfit only once (in episode 6) in the main story. However, the staff were surprised to hear that there are some dubious female fans who think this look is very lovely.
Catherine is supposed to be a sisterly-like presence, no matter what, is the reason Trowa appears more mature due to actor Shigeru Nakahara's subtlety? Recently, more of Trowa's human side has been exposed, and the subtle struggle between his cool side and surprisingly emotional side adds depth to the character.
"In tactics of promoting a character, it can give greater effects to reveal the positive aspects later..." Trowa would surely analyze it this way. Or maybe not...