This colour comes from the bark’s natural structure and chemistry, including compounds such as tannins that help protect the tree from pests, fungi, and environmental stress. The bark also peels in thin layers as it grows, which can make it harder for mosses, lichens, and other organisms to firmly establish on the surface.
You have left out some important information:
Does the shiny bark make it hard to climb? Or do the barky ring bits make it easy to climb?
Asking for a monkey friend.