Moisture will reflect the shorter wavelength (blue) component of light more easily than longer wavelength colours (yellow, amber). Thus it is commonly thought that lamps with yellow or amber lenses are better for bad weather conditions. However, the amount of glare created is also affected by the relationship of angles between line of sight and the angle of the lamps. When using a lamp with a coloured lens or filter the amount of available light will reduce, affecting visibility & colour definition. A normal lamp with an optimum light distribution pattern & mounting position can produce better results than one with a coloured lens or poor light distribution. Ultimately, the answer to this question lies with how the individual users themselves perceive the illumination.