I use color paper for my client letter and invoice when I prepare tax returns. (I use a color for the letter and a different color for the invoice.) This way the letter and invoice are distinguishable from the white copies of the tax returns. I've experimented with pastel copy paper from many office supply houses and have found those sold by Staples have the best shades of the color. I'm not sure how else to explain it. They're very pleasing to the eye and not tacky. They seem more tasteful.