All the major Brands of firearms manufacturing have Customer Service departments, including Colt.
The unvarnished reality is that a maker can only afford to junk so many parts - they cannot price their goods completely off the market, and they can't test their products sufficiently enough to keep them "new" at the point of sale. What they do is set a level of acceptable defects getting thru and let CS take over to satisfy that number of questionable guns that will get thru.
After that the company manages public opinion as best they can with advertising and bending over backwards taking care of the most vocal and disappointed customers. In the bigger scale of things, Colt does a good job overall with that - even in the face of bankruptcy. They will most likely change hands in the next three years and it remains to be seen what their future will consist.
Worst case, buy for your collector status rifle now. Otherwise, it's still a decent shooter.
But, to emphasize what the OP put in bold type, 100% reliability isn't going to happen. We all assess our risk differently, some use reject or surplus ammo when others might only use premium loads for self defense. Some might have a cleaning procedure that is casual, others literally breaking down their personal weapon daily for a wipe down and lube. Some use whatever magazines they find on the shelf for sale, others cycle theirs thru with a mind to discard and crush any that have issues.
Nobody can guarantee that the one rifle purchased will be free of any failures whatsoever for life. There's been plenty of posts by gun owners over the years, paying high prices for highly reputable guns, and there seems to be that one guy who gets the lemon.
The best that can be said is that Colt is pretty good, and we wish you luck. Nobody but the Colt Customer Service Department will back that up with free repairs, tho, regardless of how much they like the roll mark on the lower.
C'mon, we can find defiantly loyal owners of Brands most of us wouldn't poke with a stick. The manufacturers are playing the odds and so do we. It's a game of discerning the reputation by word of mouth and no matter what we insist, it still boils down to that one rifle in the hands of the buyer - what he expects trumps anything we might like to assure him will happen.
Having been deployed and serving under the philosophy, I would say Colt is the least worst vendor. It would be hard to do better for the money, they are a national supplier. But, 100% reliable? It's a matter of perspective and at this advanced stage of "maturity," I can't say that is the appropriate focus.
Guns fail regardless of our opinion. Better to prepare for failure than hope for perfection in something made by other humans.