Warping Wail is criminally underplayed. It's probably one of the best charms ever made. The first mode can snipe a lot of utility creatures like Esper Sentinel, Soul Warden, or Blood Artist for good. The second mode counters almost every board wipe in the game, in addition to hitting big game ending sorceries like Torment of Hailfire or Breach the Multiverse. Last, the third mode is just an emergency blocker, but you could clamp the Token or use it to turbo a 4 drop Commander on turn 3.

But how much of a cost is the color pip to splash in your deck? I honestly say not that much. Let's take a Boros Manabase and how most of you faggots would build it: You always run your Painland and your Lorwyn Filter as well as Sol Ring and Talisman of Conviction. That's 4 sources base. Next you probably run Reliquary Tower, Scavenger Grounds and the two Boros utility lands: Sunhome and Slayer's Stronghold. We are now at 8 colorless sources.
From there you have so many options: Starting Town is another unintrusive way to fix your colors while still proving colorless. Abstergo Entertainment is a filter land with built-in recursion and Graveyard hate. Sol Lands like Ancient Tomb or Temple of the False Gods can cast Warping Wail by itself.
We can go deeper too. If you're in White, you could drop 1 of each basic for Ramunap Ruins/Shefet Dunes and run Sand Scout as a really good ramp creature (which would also give you access to Arid Archway as a bounceland). Budgetfags can run Promising Vein or Ash barrens for colorless lands that aren't completely dead.
I have a 3-color deck with 10 colorless sources in 41 lands + 3 rocks and I wouldn't even bat an eye if this was castable.

I think especially mono-green should want Warping Wail because every mono-green deck loses to All is Dust and Farewell.
I probably wouldn't play it in Blue decks. Mono-black seems suspicious too, because you want as much swamp mana as you can get to abuse Coffers.