Tugmaster and others are right, color of a forklift is for marketing only. The Manufacturers want to isolate themselves from each other. Raymond, Crown, and Clark all use horrid colors but when I would like for the unit called in. Operators would always give its color. My understanding is that Raymond purposefully colored oils and etc. orange and sold them for use in forklifts.
Design of the forklift is matter of function. The Straddle design (supposedly a Raymond breakthrough) changed space utilization. In fact all material handling is about storing something as efficiently as possible-saving space, time, and safely.
The forklift manufacturers would be a great place to gather information. Its getting them to be quiet that is hard.