It won't be too bad. The Pre-release for shadows over innistrad I ran a 5-color human/spirit deck using investigation and I actually won my first match with it. And that was the first time I EVER used a 5 color deck. It seems difficult but when you have the green
vessel of nascency,
fork in the road combo with your
not forgotten you've just produced up to two-three types of colors from your deck in one turn. Play those cards in conjunction with
stoic builder and you'll be pitching lands and then adding them right back to your hand. You could get all the colors that you need in under 5 turns when adding the right cards that scry and
recycle. Also the dual lands will alleviate this problem since you're getting two for one card.
Also the big thing to consider is this,
geist of the archives lets you scry EVERY upkeep. That means every turn you're deciding do I want to keep this card or not. Have multiples on the field and use investigation or
catalog or the
nagging thoughts and you're setting up plays where you can scry, draw into the cards that you want and then madness away the cards that you need to play in those situations. A 4-Color deck is not at all hard to operate, it's just adding the right cards that create a flow to the deck. For example; Most people before Innistrad probably would not run a deck that sacs their own lands. But with
the gitrog monster you can sac your land, play EXTRA land and get a EXTRA draw when one hits the yard. Having lands that come back or having enough basic that you want to mill works best. Also
crawling sensation helps with
the gitrog monster because you can let the frog sac the land without you milling and then you can still get an insect token. That is an example of synergy and that's exactly what you can have as well in this deck. Decks are puzzles waiting to be solved.