A Guide to Rokugani Heraldry (2010)

From the introduction:

Heraldry in Rokugan is less formal than heraldry in the West. All samurai sworn to a Clan wear the mon, or Clan symbols and colours. Nobles often wear a kamishimo or small vest over the kimono that bears the mon, on formal occasions. A samurai wear his Clan’s mon the back, and the mon of his Family on his left sleeve close to his heart, or his right sleeve to guide his sword.

A samurai usually incorporates his Clan’s colours into his formal clothing; private clothing tends to be drab grays and browns. Samurai often wear hats for formal occasions, which can be very simple or very extravagant, depending upon the wearer’s mood.