There are certainly what I would call "heritage" colors such as JD, Massey,Kubota,etc. Ford chose a blue color that they've had for a very long time after their red and grey and white tractors. The historical part is very interesting because I for one would like to know what influenced some companies to select their colors. Blue is the most popular color for us humans. Did Ford base their color on this association? There are all kinds of psychological aspects to colors beyond popularity and most of this stuff was never studied in the early 1900's so maybe colors were purely randomly selected based on what the CEO's of the time liked. What is also interesting is how far reaching some of these decisions are where they are still effecting us today. Can you imagine the uproar if say JD changed their color scheme to maroon with gold wheels? I think the earth would tilt off axis no matter how good it looked.