Animating gradients

Hi,

I got this tutorial because I really wanted to know how to animated gradients (amongst many other things)
Cool effect in chapter 14.

SO… now I understand how to do this in a layer - but what I really wanted was to be able to use this in a SpriteKit game.

I’m super confused about how I might be able to add a gradient layer into a Scene of a SpriteKit based game?
specifically, I wanted to make a blue sky, that animates into a sunset and night etc… (that would be pretty cool!)

is there any advice on how to get the gradient into a sprite kit scene ??

thanks a million !