Without much darkness? What deck splashes darkness, and for what reason?
I guess a poison player can splash darkness to drop parasites for their infection ability. Other than that, let's review the darkness cards:
Dusk shield: If you're splashing for defense, splash light for the sundials, because you get 2 cards drawn with that.
Life Drain: Dark only card.
Steal: A great card for rainbow, but if you're running earth, you should splash gravity to use pulverizer instead, or if using gravity, splash earth to pay for its initial drop. Explosion is also far cheaper as a splasher, and sometimes you don't want to override your own weapon or shield.
Dragon: Splash for dragon? WTF?
Nightfall: Darkness+poison does not work well together, that it does not. Those of us who have played incarnate and beaten him just about every single time know this. Granted, he could have packed pests and steals, too, but that probably wouldn't have made him much better.
Vampiric dagger: LOL?
So once again...this card fails. You only splash dark for steal.
Other colors:
Light: Upped sundials.
Fire: Explosion
Earth: I'm not sure whether Earth/Time/Water can work by just going on a massive quanta-killing spree and rolling over with a couple of big monsters...