Here is where lands that produce multiple colors like Simic Guildgate and Temple of Mystery come in handy
Prototype allows us to pick from two casting modes: do we want to pay an exorbitant amount of colorless mana for a big splashy robot, or a more reasonable amount of colored mana for a miniature, Hotwheels version of that same robot
Its tied to elemental types like Fire, Water, Grass, Lightning, and Psychic
Sevinne allows Jeskai to move into a more controlling build, grinding out games with value spells and the ability to double game-ending spells like Devil's PlayDevil's Play, Increasing ConfusionIncreasing Confusion, and (in some builds) Increasing DevotionIncreasing Devotion or Call the SkybreakerCall the Skybreaker
While we already have cheaper draw engines off dying creatures like Morbid Opportunist and Grim Haruspex, these are all capped at one card per death trigger