cupreous

noun
  1. 1

    A reddish-brown color, like that of polished copper.

adjective
  1. 1

    Of or of the nature of copper.

  2. 2

    Containing copper.

  3. 3

    Of a reddish-brown color, like that of polished copper.

Source: https://en.wiktionary.org/wiki/cupreous