The red mage reference in question here is that of Final Fantasy lore. The class of character that was the definition of a jack of all trades; they could fight with weapons and equip actual armor yet they were capable of casting white and black magic. Not to mention that in most every instance of the appearance of the red mage, they had an awesome red hat, often times with a feather in it.
Sounds appealing, being able to do a little bit of everything, doesn’t it?
The drawback to the red mage was however, is the fact that they were a jack of all trades – meaning that they were neither a king nor a queen of any of them. Their fighting prowess had a ceiling far lower than that of any other class that specialized in fighting strength and abilities, and their speed and agility were vastly middle of the pack, and could go no higher. When it came to casting spells, sure, they were capable of casting both white and black magic, but they eventually hit a wall with both, that they are incapable of surpassing, while white and black mages can continue on to learn a litany of spells exclusive to just them.