Looking good! On the blue ... I think the slightly lighter blue cabling will be fine. If you want a tubing that is closer to the cabling, you can try the Primochill LRT ... it's available in 3/8" by 5/8" :


(Photo from Performance PCs)

I used the 7/16" version in my earlier iteration. And, to respond to Mr. SiGfever --- I agree, you can't finish the build - unless, you promise to go right into another!