The wild rice kernel (the part we
eat) is tightly surrounded by a protective hull. If you peeled the hull
cover away, the kernel inside appears dark with a greenish-purple hue.
When damp, the windrows have a dark colour. But when the hulls on the
outside of the windrows are dried by sun and wind, [left] they give
the windrows a golden-brown colour. [middle]
All by themselves, hulls look like little bits of straw. [right] They are fairly thin, and so the colour of the wild rice kernel inside can often be detected, especially by someone with an experienced eye. The kernel will gradually change from dark greenish-purple to dark brown and black.