To answer your question. Yes they do disintergrate & discolor if they are not sealed properly. I have used this site to buy the product you actually need.
http://www.flooringsupplyshop.com/sealers-and-care... What you ae looking for is The one step easy to apply "Glaze "N" Seal" waterbase Sand Stabilizer & Sealer for interlocking pavers & bricks.
I hope you like this site as much as I do for certain progects