Building an AR-15: Best Furniture color?

Im building an AR-15 and have been researching various stocks grips and handguards. I've decided to go with Magpul they have a great reputation and their prices are pretty good. My question is what is the best color to go with? They offer Black, Olive Drab, Dark Earth and Foliage Green. Which is the best universal color as far a camouflage?