I agree with the other members, currently Colt have only 1 year of warranty but I would advise to get your Colt from a distributor with lifetime warranty for example Davidsons, if you don't like something with your AR they will replace it if in stock within a few days.
There was a member here a year or two ago that had a bad kaboom that was investigated by Colt and was caused by weak brass case material, Colt replaced the whole upper half, checked and repaired the lower under warranty and they went after the ammo manufacturer to pay for the warranty cost.
With Colt you most likely won't need to use your warranty, I only had a small sample size of 7 which I used to have and currently I have 5 (carbines and rifles), I had not broken any parts just replaced worn parts, I used my AR from 10K to 20K before selling them and then getting a newer Colt model.
I've got a total of 43 years owning Colt AR and I'm a very satisfied customer.