Red onion and purple onion are common vegetable varieties, but red onion has more advantages in taste and nutritional value. Red-skinned onion has a red or purple skin and a white interior, which is crisp and tender, and is more suitable for raw food or cooking. At the same time, red-skinned onions contain high anthocyanins and carotenoids, which have many health-care effects such as antioxidation and cancer prevention. In contrast, the skin of purple onion is purple or deep purple, and the inside is white or lavender, which is spicy and suitable for cooking. Therefore, from the taste and nutritional value, red onion is better.