The basic period is Late Victorian, around the time when bustles were
popular. Don't let that cramp your style: poor people are a bit old-fashioned, rich people are terribly modern, and some folk just like the eccentric. The genre of the game is Steampunk, and that means Weird and Wonderful. Some
The de l'Eclaire family are French, posh, fond of light colours and natty tailoring, tend to smell of ozone, gunpowder, or expensive perfume, and often have boofy, poofy, frizzy hair.
The Drakenwyrm family are quite sinister, from mountains in darkest Europe. They're fond of rich, dark colours, heavy swagged cloth, and tailoring that suggests animal features.
The zeppelin pirates are fond of ruffled shirts and swaggers. Goggles might be useful.
Scientists favour labcoats as a sign of their status. Pin-sharpeners are more working class. Travellers from Britain are neat and straitlaced. Everyone else, go with your heart.