Unfortunately, there are not many (any?) current, affordable books that only cover Dutch. And purchasing an APA or ABA standards book, while recommended, will get you information about every recognized breed, which is a little much for an introduction to Dutch Bantams.Does anyone know or recommend a good book describing the colors and combinations of the Dutch Bantam or Old English?
I would suggest using the internet to search for photos of the various color varieties, and I would start with the US Dutch Bantam Society website, www.dutchbantamsociety.org. Also of great value is the website at www.dutchbantams.com. Being from the states, my info is understandably US-centric; there are many good sources outside of the US, particularly from England, where they are really serious about Dutch. (and Europe has many more recognized color varieties than in the US).
I am not sure about the Old English, as they are a completely different breed of bird. While it is common that people visually confuse Dutch and OE breeds, they are not related in any way. Posting your request on an OE thread would probably be more helpful.
(As an aside, Dutch people may appear to be hardheaded and unhelpful when fielding requests about Old English-ed "dutch bantams." It is only because we feel that we are on the front lines of a battle to keep "foreign" blood out of a truly remarkable breed. Purebred Dutch Bantams are worth seeking out.)