Patch 5.7 fixed potion gems taking first turn from the player. Two new bugs were added.
Patch 5.6 fixed heroic gem conversion, explosion, destruction and removal and how these relate to and interact with gems of their respective colour.
Heroic gem creation, troop colour interaction and accounting for colour gems in calculations are still broken. Potion gems grant mana to the enemy and trigger traits when activated before first turn (explosions, skyfall matches).
Partial list of bugs and troops affected and developer responses:
5.6 [Investigating] The Grey King - Does destroy colour gems but will not deal damage to enemies of that colour when cast on a heroic gem.
5.6 [Reported] Sycorax, Honor, Courage etc - Can be cast on heroic gems, will double colour gems instead.
5.6 [Radio Silence] Tuliao - Can be cast on heroic gems, will not enchant troops of that colour.
5.6 [Radio Silence] Shaman of Set - Can be cast on heroic gems, does not account for colour gems.
5.7 [Reported] Potion activation at the start of battle assigns mana to the enemy.
5.7 [Reported] Potion activation at the start of battle triggers traits.
E2: Updated for 5.7