Stale Water (Part 2)
A human would have considered it amazing, but to the elves, it drove them mad with frustration. With looks and mana equal for everyone, it meant that the most important defining trait for an individual was talent.
The color of a mana core had nothing to do with elemental affinity or magical skills.
To most elves, it meant that they were forced to spend hours training just to not kill their clanmates by mistake. Having no talent for magic was far from uncommon, but while a red-cored human could barely light a match, their elven equivalent had to be careful even while conjuring a breeze.
With a bright blue core and true magic, a lapse of judgment would turn it into a stray bolt of lightning or a wind blade with potentially deadly consequences. On top of that, those lacking talent were doomed to perform menial jobs their whole lives.