Why are copper tracks orange-gold?
Because that board has been gold plated. Ironically, that saves money; copper tarnishes, and would need expensive cleaning immediately before soldering. And gold on the contact fingers makes for reliable connections. Other platings are possible : tin or silver, and formerly lead-based solder. Scrape some green solder-resist off the earth track and you would see a more reddish metal, though it would take a few months to tarnish to the colour of those pipes.

EDIT : the gold plating on the contact fingers may be a different process (thicker plating, to resist wear) - plating on the board itself will be VERY thin.