Hi Gamera;
As far as SteamPunk colors. Think of the world at the end, or near that point in Victorian times. Colors weren't bright, Unless You might be a lady working the Worlds Oldest Proffession, a Clown, or some outrageous bit of Friffery from the females in a landed family!
"Oh Deah! Those Ruffians are quite Rowdy in their Dress, Eh Wot?" Brass, not all polished along with Steel, Wood and some darker Satin colors from say the color of a Yacht's Bottom. Dk.Red or Dk.Green
Or we must not forget Soot, Rust, Grime, and corrosion of the forms that grace Brass, Bronze and Copper! and lastly worn or Fancy worked wood! Aged and Mismatched canvas too!