Were John Deere tractors always green?

No. To tell the truth JOHN DEERe tractors were painted many different colors over the years. Back in the 1950s and 1960s, John Deere two-cylinder tractors such as the 420/430 and 320/330 were painted highway orange, highway yellow, and yes there were a handful painted red. John Deere wanted to win over as many customers as they could so when you ordered a tractor, you could have it painted a color other than traditional ag green and yellow for a low flat rate. Many state highway departments did this to make their equipment easily identifiable. Even today, some tractors built specifically for construction purposes are paited industrial yellow, so yes there have been many different colors available (by special order) on John Deere tractors over the years.