Walnut Claro Burl — Heartwood can range from a lighter pale brown to a dark chocolate brown with darker brown streaks. Color can sometimes have a gray, purple, or reddish cast. Sapwood is nearly white. Wood from orchard Grain: Grain is usually straight, but can be irregular. Has a medium texture and moderate natural luster. These characteristics distinguish Walnut Claro Burl from similar species in the veneer market.