I have a dell AIO 966 printer for school I have to print alot of powerpoints most are in color I can not find how to make my printer turn the black or color backgrounds with white words into white backgrounds with blac words my friends say change to grayscale but there is no option for that I tried black and white photo option and draft , and normal nothing works HELP I have used alsmost a whole cartridge of expensive dell ink in just 1 and half weeks