UncleScrooge on 11 December 2014
Not just NES Zelda games were gold. Ocarina of Time and Majors Mask had a special first edition with a gold cartridge. When Wind Waker was released they couldn't make a golden CD so they released a special pack with Ocarina of Time + Master Quest included on a second disc. It really is sort of a tradition with Zelda in the west.
As for Captain Toad, I have no idea. But I wouldn't call it a trend. They probably just thought it looked better.
