4 To soften the acid-yellow color, collage over the Yellow Pageswith torn pieces of white tissue paper. These can be a little larger so the collaging goes very fast. Don’t cover the area too perfectly; let layers overlap so that you get a pleasing mottled affect. Start with about 2 layers of tissue, let them dry, then see if you want to add more. The tissue is barely obvious when wet, but once dry, its softening and whitening effect is quite dramatic.