On first glance, the rainbow eucalyptus tree (Eucalyptus deglupta) doesn't seem like something that could exist in nature. This unique tree, indigenous to Indonesia and the Philippines, begins chartreuse and dark green before turning into vivid shades of lilac, rusty red, and burnt orange as the tree grows older. Older layers of these colors peel off, displaying the full rainbow array of hues. Little research has been done to examine how and why these colors change so dramatically. One theory is that each bark layer has a one-cell-thick transparent overlay. Over time, the clear layer becomes flush with different colors of tannins and the accumulation of these tannins as well as a depletion of chlorophyll may lead to the colorful bark layers. We've collected some awesome videos on this topic. Watch them now to learn more.