To breed a Blue Fire Dragon in Dragonvale, mate a Fire Dragon with a Storm Dragon or with a hybrid dragon that has a Cold element. Alternatively, mate a Cold Dragon with a dragon that has the Fire element.
Dragonvale Blue Fire Dragons are very hard to breed, because they contain two opposing elements: fire and cold. One of the conditions of breeding Blue Fire Dragons is that the process is non-linear and breeding does not succeed at the first or even the second attempt. However, repeated attempts will bring the desired result. The egg of the Blue Fire Dragon is red with snowflakes. Waiting time for it to hatch is 12 hours.
The easiest way to breed the Blue Fire Dragon is to mate a Storm Dragon with a Fire Dragon. Another method is mating a Fire Dragon with a Hybrid Dragon. The latter needs to contain the Cold element. Examples include Ice Dragons and Snow Dragons. The hardest way is to have a Cold Dragon mate with a dragon that has the Fire element.
Do not try to use Cold Dragons for mating with a Fire Dragon, as their opposing elements will cancel each other. Another combination that does not work is a Fire Dragon and a Mountain Dragon, as this will result in a Mountain Dragon Egg. If a Blue Fire Dragon is already available, breed it with a Fire Dragon to obtain a Blue Fire Dragon baby.