I find the Charm cycles, while useful, aren't nearly exciting enough to be ran in multicolour sections. imho your multicolour cards, since they fit in the least number of decks, need to be "cool" enough to draw you into the pair. I won't decide to go UG off a
Simic Charm and won't even pick it up speculatively, though I'm happy to pick it up if I'm firmly in UG. However, I
might go UG off a
Kiora, the Crashing Wave because she's an interesting Planeswalker, and I will be happy to pick her if I think I'm going in that direction. Personally, I build my multicolour sections to feel as intriguing and fun as possible; generic utility belt effects do their job best in the mono-coloured sections. A
Giant Growth that might be an expensive
Ranger's Guile (sans stat boosts) that might be a
Consuming Vortex can certainly do fine work, but at the end of the day, I don't care about it and I don't get excited by it. Odds are, neither will your drafters. Just my 2 cents, anyway.