Any kind of irradiation will cause effects in the material, some parts of the spectrum are more aggressive than others, but there is nothing especially damaging in the sunlight, except that it is more powerful than usual lighting. If a material will react to light at all, it will probably be the ultraviolet part of it, which is present both in sunlight and halogen lighting, however I believe most halogen lamps have some sort of protection against that (UV shields and such). Unless you use too powerful a light, I don't think you should worry about that.