It will just wiff far too often, and going down a card for no effect is brutal
It does nothing for loss of life sadly, though
The color pie balance in the cards feels kind of random though
Mondrak, Glory Dominus Mondrak, Glory Dominus from Phyrexia: All Will Be One is an incredibly strong token doubler in white, and an excellent token commander
just about anything that has you spending mana to put a card on the stack and attempt to resolve it counts for expending
Im not gonna say casting multicolored spells is niche or hyper-specific, but giving Lilah, Undefeated Slickshot a specific condition like that is definitely a good slow-down on power creep, especially in an archetype like spellslinger, which uses tons of monocolored spells