Unfortunately, color inks aren't a good idea for archival documents. Even if the toner is chemically stable, the color printing process involves laying down four layers of pigment. The result is a thick layer of toner, which tends to crack when the paper bends. This brings us back to the paper question. Most papers contain acid, which slowly but literally eats them away.
Newsprint is high in acid.
You've probably noticed how quickly newspapers yellow, especially in the light. They also become brittle with age. It's remarkable that even this worst of papers lasts a hundred years or more if it's handled carefully. If you want your documents to last, print them on archival quality paper. Papers are either acidic or alkaline.