I've always enjoyed fireworks and photographing them! My best results have always been with transparency film as first choice and B&W neg as second choice. With the large areas of darkness, color neg can look muddy particularly if machine printed with no correction.
There is a lot of latitude, and a medium speed film with smaller aperture and a longish exposure, up to several seconds, will capture the spark trails quite easily. Sometimes two of three overlapped exposures on the same frame can produce interesting effects.