It's because most light aircraft painted in all over white (or most other colours for that matter) look very bland and shapeless. The "stylists" who wanted to sell them decided that a cheat line along the side visually adds length to a stumpy (eg PA-28) shape. I tend to agree with them. I had an Aerobat painted with an arrowhead in red and blue flowing down the side and up the tail fin. Looked lovely until those 92mph winds flipped her over.
dublinpilot there are quite a few aeroplanes around with "unconventional" paint schemes. If you've seen pics of
stiknruda's purple Pitts you'll know what I mean. RayBans recommended
camaro you can paint any aircraft any colour you like. The only rules apply to the size of the registration letters and their contrast with the background colour. Oh yes, and the obvious ones like don't paint over the windows, especially the front one
