Mmmmm, To me it just looks like stained epoxy? Why not just embed a colored film in epoxy.
I remember reading the paper this is based on when it came out in 2016. I also seem to recall just some pie in the sky kind of potential uses for the material. Still kind of interesting.
That’s basically what they are doing. I just watched a video yesterday based on a newer process than what they used in the above instructable and all you need to do is cut some thin sheets of wood (~1mm) paint them with hydrogen peroxide and leave them in the sun. That will bleach the wood leaving it white. Then epoxy the wood strip. The epoxy will fill the wood making it clear.
I’ll post the video if I can find it.