It looks like for the official Code 16 that I don't need chains today for my Power Wagon even though it's implemented, but then there's the SECRET Code 16 on the same CDOT website. It states that I "must have chains" for my 4x4, but it doesn't state "need" chains. The short worded chain requirement signs are even more confusing when you're driving pass them at 75 MPH. I have never used chains on Colorado highways.
Code 16/Passenger Chain Law: All passenger vehicles need chains, except for 4WD and AWD vehicles with all-weather tires with 3/16 inch tread depth.
SECRET Code 16:
Passenger Vehicle Chain Law
During severe winter storms, CDOT will implement the Passenger Vehicle Chain Law. This is the final safety measure before the highway is closed.
When the Passenger Vehicle Chain Law is in effect, every vehicle must have chains or an approved alternative traction device.