I wish to heavily invest in a monoclored control deck, and I would love to hear your advise as to which one.

Green and Red have nothing to offer to my knowledge. So it really comes down to blue, white and black. Any advice/recommendations?

I know many people like Quinn (MWC) but I honestly don't see the appeal and it doesn't seem like the deck has much in the way of disrupting your opponents early on or any answer to combo whereas both blue and black offer countermagic and discard respectively.

Is MUC a viable deck still? I would love to play blue but all work on the deck seems dead and I haven't seen many placements with it on deckcheck.

So I'm leaning towards black because it has so much excellent disruption/discard, removal and sweepers, mana acceleration thru Cabal Coffers, card advantage thru Phyrexian Arena and several fantastic options for finishers.

And it seems some of the recent Train Wreck players have shifted away from splashing green to play Deed and opening themselves up to Stifle and Wasteland when Keg, Disk, Stone and Damnation can serve the same function for less mana and without neccesitating a splash.