2013 Kona Jake, 2015 Kona Jake the Snake, 2008 Kona Major Jake, 2013 Kona Jake the Snake, 2006 Kona Kula, 2012 Ridley Excalibur, 2008 Surly Long Haul Trucker, 2001 LeMond Buenos Aires, 1984 Pinarello Gran Turismo, 1982 Trek 614
Typically when your bike is heavy it's because your parts are heavy. A really heavy frame typically weighs no more than 4.5 pounds. All but the very lightest frames weigh over 2.5 pounds. A steel fork might weigh as much as 2 pounds, and a full carbon fork will generally be just under 1 pound. So going from really heavy to really light in the frameset might save you 3 pounds. That's nothing to sneeze at, but you have to decide for yourself if it's worthwhile. Also, I think you've already got a carbon fork, and I'd be surprised if that frame weighs over 4 pounds. You probably would be saving less than 2 pounds.
That Colnago frameset won't work with disc brakes, so that's probably a consideration for you. Most carbon framesets these days will have some kind of oversized bottom bracket and head tube, so those are additional parts you'd need.
Making a bike lighter is always a very expensive project, and it's not done until you've replaced everything.
Why? Seems like you're kinda new to cyclocross. Do you race? If it was me I wouldn't bother, but it's your money. And yeah those are perfectly functional but not high end lightweight components. Spend time getting faster, stronger and lighter. I don't know about you, but I could lose about 8 lbs off my own frame before I start worrying about the weight of my bicycle frame.
Have you weighed the frame? The frame on my Fantom Cross Pro (54cm) weighed exactly 1500g and the carbon fork was another 660g. It would actually be a challenge to find a good carbon CX frame that was more than a few hundred grams lighter. I know the Outlaw uses a different frame than the Pro, but I wouldn't make any assumptions about weight without stripping it down and putting it on a scale.
I don't race. I just don't like the feel of Fantom Outlaw frame. Especially after a day riding my CAAD10. The Fantom doesn't feel as stiff and responsive. But after looking into it more it seems very costly. :/