If you are referring to the speed build kits in the brown foam board vs the few of them in the new white... As a new builder I don't think you'd really notice much difference. A lot of people like white better , maybe they fly without paint or they want to put lights in them but I found the brown foam board quite resilient and easy to work with. I wouldn't let the color of a speed build kit sway my decision
I've done a review video on the thicker maker foam vs the brown foam:
but I haven't got the review of the 5mm white vs 5mm brown done. I have all three types and I've been building with all of them lately. What I can tell you in a quick rundown is that, if you are a new builder, the bigger difference is doing a speed build kit vs trying to cut a model out yourself. You will not notice a difference in Maker Foam vs the Brown waterproof stuff. From my tests, the maker foam is less waterproof, but easier to paint which seems like a wash because you, more than likely, intend to paint most models that might experience a bit of moisture. Nearly every other aspect of it is the same.
My biggest suggestion would be to buy a speed build kit, either brown or white, then buy a box of Maker foam. Take all of your parts, trace them onto the new maker foam and cut them out by hand. Save your actual kit to build repairs, or another whole new airplane. This is a technique I've used on nearly all the kits that i've done. This will ensure that you always have replacement parts should you crash and damage your plane... but thats just how I do things...