This barn can be brought back to life with so many colors. Do you want a red barn? A lighter gray? A new modern look? Keep it older looking? Not knowing what your color preference is, I myself see this in a beautiful, light, warm gray to blend in with the roof. I would use an Olympic solid stain called Cape Cod Gray. It will really refresh the look of this barn if that is what you want. I would also give it a nice red door. Whatever color you choose, remember that preparation is key here.  Here' a link to Olympic to help you out. You can copy and paste this if the link doesn't work: http://www.olympic.com/stain_products/exterior_stains/index.htm