I need help with a three-color mana base.

hey guys,

so for most of my mtg career, I have dabbled in mono and dual color mana bases. occasionally, I have gone so far as to splash a third color for some extra utility. however, I have an idea for an Esper deck (w/b/u) and I have no idea where to start on building a well-rounded mana base for it.

so some assumptions: lets say I have an unlimited budget for mana base, my max CMC is 5, and theres an equal distribution of all three colors at all points on the curve. what I'm looking for is a starting point to go off of, and then I can (hopefully) tweak it from there.