Although Kuroka doesn't has fixed design, he sometimes drawn with glasses and oriental clothes. For example, in here illust/50696748 page three first frame is Kuroka. But his design can vary. He may change clothes. Glasses may be fake. Particularly, before he leave Belfort family, he might wear differently.
And, yeah, interior of the Belfort mansion event is very good idea. I'll make up an event about that in chapter three. :D