Scroll down to the pic of the cock pit and you will see the layers.
Still not seeing it. We'll probably just have to agree to disagree here, which is fine, but let me try this first:
Think about the rotomolding process. You put the plastic inside a closed volume (mold), melt it and spin it on at least 2 axes to distribute the plastic along the inner surface of the mold by way of centrifugal force. It has to cool enough to solidify while spinning, so that the plastic doesn't just run to the bottom of the mold. When they open the mold, they have to cut out the cockpit, because the hull is completely enclosed. Now, how do you suppose they get that 2nd material inside the outer material, then melt it while keeping the outer material cool enough to retain its shape?
I still think this is just colorant distribution. The plastic at the surface of the mold is the first to set up, so it's got the "bombpop" color scheme from how they put the plastic in the mold. Probably only rotated axially at first to get that. By the time the very inner surface of the hull sets up, it's been rotated on multiple axes, so the color's all mixed up, but it's still all one base material throughout.
Funny thing is that I had a bombpop Y myself (also crosslinked) back in the day, and I busted the shit out of that thing eventually. Finally sunk for good at OBJ, where this picture was taken on Ankle Breaker...