A pleasant spring-time look, this. The tapestry-like stripes and length to the legs, and the discreet ruffles combined with a slim fit ensure these evade giving the pajamas impression that is the pitfall of most striped trousers. Just make sure the top is also at least partially tightly fit. I'd also swap the shoes pictured into something more Victorian-inspired, something in black or a nice earthy shade of green.
Found here. The Burning Circus collection isn't half bad, really.