In Japan, the most important sector of the market is the ‘Kei Car’ category. If your car falls into this class, below a certain size, engine capacity and weight you pay drastically reduced tax and insurance rates. Many Japanese car manufacturers embraced the Kei Car and Honda was one of them. The Z600 pushed the limits of the Kei Car regulations, but despite its limitations, the Z600 had no problem keeping up with traffic. All UK Z600s were painted Orange, with a ‘Starsky and Hutch’ style black stripe running along the flanks.
info from Octane