Woollen tweed coat, maybe Harris tweed? The wool woven on a Scottish Island into multicoloured flecks that look brown at a distance. Tweed was often dyed with natural dies, for example onion skins to make yellow or heather and lichens. Then steeped in a mordant to ‘fix’ the dye. A mordant is a chemical that prevents the dye running if the cloth gets wet. Urine was often used. It used to be collected from residents for the process.
Tweeds are very insulating, they can absorb a lot of rain water but still keep you warm. The sheeps wool is very useful for making materials like felt too for caps and hats.