DS is Y1 and a reasonably able reader. At school he is on purple books, but he hasn't been heard 1-1 since October/November. They make them read every book at each level before moving them up. At home he can and does read higher, roughly white level I'd say.
Does it make sense for him to get 'comprehension' homework at blue level? I.e. a blue ORT Biff Chip and Kipper book (which he read as a school book about 18 months ago) with a matching work sheet, with very simple multiple choice questions.