H. F. Colman was a prominent stamp dealer in Washington. Servicers Hammelman and Hungerford worked part time in his store. There was a typewriter with a blue ribbon at the store since most Colman and some Hammelman and Hungersford serviced covers have blue addressing.
Registered covers in Washington did not have dated postal markings on the fronts of the covers, but had registry date stamps applied on their backsides. The above cover has a registration number significantly different than those on the Strasser and Ward FDCs because it was processed at a different postal station.
The first Colman FDC that I am aware of is for the Alaska-Yukon-Pacific Exposition Issue of 1909 (Scott 370).