It would be nice to have colour illustrations or photographs of ideal patterned feathers. I realize that the feathers can differ somewhat from one area of the body to another, but things like penciling and lacing don't vary much; don;t need to do every colour of each pattern, but just the patterns themselves.
Don't sweat the pictures overmuch. Poultry judges are not supposed to take these artist's renditions as examples of perfect specimens, anyway. I quote from the APA SOP: "The written text is the description of the ideal bird."
In older editions (I have a 1915 edition) all pics are "half-tone illustrations of retouched and idealized photographs of living specimens." I personally wish the APA would go back to that method, but in color, too. These old illustrations are leaps and bounds more informative and detailed than the newer colored artwork, IMHO.
The British Poultry Standards uses color photographs, not really sure why the APA and ABA have chosen not to... except that it'd cause a great big fuss over who had the most "perfect" specimen!