Hi Helen, Happy New Year to you!
I tried both patterns and both ways of colouring.
Here's the cube-in-a-cube version, pre and post colouring.
Here is the base cube pattern. I played around with a gradient layer and blending.
I love how, when you stare at these, you can see more shapes within the shapes.
Thought I would add this image as I quite like it as a graphic by itself!