Copper and copper-alloy colours. 

C11000 — Copper (Cu 99,9%)
C22000 — Commercial bronze, 90% (Cu 90%, Zn 10%)
C23000 — Red brass, 85% (Cu 85%, Zn 15%)
C26000 — Cartridge brass, 70% (Cu 70%, Zn 30%)
C28000 — Muntz metal, 60% (Cu 60%, Zn 40%)
C38500 — Architectural bronze (Cu 57%, Pb 3%, Zn 40%)
C65500 — High silicon bronze A (Cu 97%, Si 3%)
C74500 — Nickel silver 65-10 (Cu 65%, Ni 10%, Zn 25%)
C70600 — Copper–Nickel (Cu 90%, Ni 10%)
Self-made with info from copper.org.
Metallos