The weapon in question should be a wooden club. I'm not sure about that particular ethnic group but red and black were colours commonly used by all manner of Brazilian Indians for decoration of their bodies and artifacts. The red dye being found in various plants, notably Brazilwood and the black often came from genipapo which is a rather sticky fruit a bit like a cross between an apricot and a fig in shape and texture. Makes a remarkably pleasant liquor, which is usually drunk for the festas juninas in the northeast.
Try googling 'Hans Stadden' or 'Como era gostoso meu frances' for a general idea about Indian decoration.