Iromuji kimono is a plain colored kimono, one color other than black. It is very useful - young women wear it at their graduation ceremony, mothers wear it for the occasion of a family celebration, not only happy occation you can wear gray or quiet blue one on condolence visit. At tea ceremony people love to wear Iromuji, since it does not bother the atmosphere. Also it is worn just for going out in town.
Depends on the numbers of the KAMON family crest on the Iromuji, the class changes. Without KAMON, it can be daily dress. For tea ceremony or celebration, usually they put 1 KAMON. With 3 KAMONs, it becomes very high class kimono.