Rumor from beta says color change used to be a permanent form change like Chameleon form or Zombie form, before being nerfed to a dispellable status ailment.
So this was actually important to the original design, you might deliberately trigger Guardian Chameleon since the color change could not be cleansed or removed. Like loading an enemy with mana to trigger Hansel’s witch killer ( spell slay ). Though Purple-> Yellow-> Purple was a problem.