There is a humble veggie scrap that can turn your plainest clothes into richly-hued pieces — red cabbage. Red cabbage is a natural source of anthocyanins, the plant compounds that act as natural colorants. Depending on factors like soaking times, fabric material, and any secondary ingredients, red cabbage can turn clothes purple, bluish-gray, or anywhere in between. But to add intensity as well as longevity to your red cabbage dye, consider adding a mordant. Red cabbage is generally effective on a range of fabrics, from cotton T-shirts to wool and silk scarves.