Fireblast is a term which recently (~2001) came to replace the term "firepower" as a Tech Spec rating. The apparent reasoning for the change is to avoid the potentially-inappropriate-for-children connotation the word 'firepower' has with guns. "Fireblast" is a neologism and an example of blastification within Transformers.
The Autobot Hot Shot carries a "fireblaster" weapon in Robots in Disguise. This refers to a specific type of weapon and is not compatible with the "catchall" use of the word Fireblast as described above.
His fireblaster shoots pink bursts of energy.