The bamboo plywood I am using to build the cabinetry for the River House is available in a natural or carbonized version. We selected the darker carbonized color for our project and I was befuddled when the first shipment arrived with a few sheets of natural mixed in with the carbonized. I even found two sheets that were natural on one side and carbonized on the other. Earlier this week, I received a make-up shipment to replace the product that was damaged during the initial delivery. To my dismay, the color did not remotely match the material I have been building with. I sent the company a detailed e-mail expressing my frustration and asking them to explain what was going on. They insisted that the replacement sheets were carbonized even though they looked like the natural version to my eye. Fast forward one day and I happened to turn over a sheet of plywood I was about to cut. The mystery was solved the instant I saw the outline of the hard core foam insulation slab that I used as a sacrificial base when cutting sheets with my track saw. It was apparent that the plywood changes color dramatically when exposed to air, presumably as moisture is absorbed.