What do you mean by "DM"??? Perhaps you mean "DN", which refers to Districto Nacional, i.e., Santo Domingo??? In any event, as far as I know, there is no single uniform for all schools in any part of the DR. It varies from school to school. In general terms, boys wear black dress shoes, long slacks and (often white, but not always) shirts or tennis shirts with the school insignia above the heart, while girls wear more or less the same but with a skirt instead of pants. In most schools, tennis shoes and short skirts are not allowed. Don't what other schools say, but the one my twins went to also required white socks.
Hope this helps.
Regards,
Keith