Sort of a cream color........why?????
It is now a known fact that flies are attracted to lighter colors, such as white, beige, cream, etc... Do you have alot of flies nesting on the eaves of your home? If so, the best you can do is to have broadcast applications around the foundation and eaves to reduce the population in the area. And then of course, when winter sets in, nature will take care of itself.
One more thing: Flystrips.