Could be some residue from the Rad that came loose from moving things around during the new build.....
Did you drain the system and refill with fresh coolant?
I have seen this with some of my water cooling loops and usually found that tilting the system to let air escape and adding more fluid and letting the system run that most if not all of the cloudiness left....
Never been a fan of clear tubing and dye myself......just went with solid color tubing to fit the build always worked the best for me.....