Good afternoon, can anyone explain to me what the different road colors mean or give me a link to where I can look them up? Some are yellow/orange, some become a darker orange, kind of brownish. I understand interstate highways & main roads being yellow & secondary roads being grayish. I just would like to know what Garmin just trying to tell me with the colors. I cannot find anything on this anywhere, so I must be looking for the wrong thing. thanks