Iodine is a natural dark violet, a non-metallic element that plays a key role in human metabolism. Iodine, for example, is slightly soluble in water and gives a yellowish-brown solution. Brown solutions are also formed with alcohol.
Iodine is usually used in an alcohol solution (called tincture of iodine) or as Lugol's iodine solution as a pre-and post-operative antiseptic. Some people do not recommend disinfecting minor wounds with iodine because of the concern that it may induce scar tissue formation and increase healing time.