Although some album manufacturers do use white paper (Mystic, Davo...), most mass-produced commercial album pages are "other than white".
Any sort of minor darkening/toning/discoloration of the stamp will stick out like a sore thumb if you use white paper. Of course, if all your stamps are perfect...

I personally prefer grayish paper. However, I'm the odd man out. Most collectors prefer natural/parchment/soft coloring of the paper. I would suggest you try out a few shades to see what works well for YOU, because it's YOUR collection!
Most copy centers have a nice selection of lightly colored paper that they would be willing to sell by the sheet.
Have fun choosing!

k