I have been busy with course prep and training courses and haven't had a chance to develop something. However, I realised that the cushion covers I am preparing for a cushion course would fit the prompt. I don't want to hem myself in with my self imposed 3D attempts. But these do end up 3D when on the cushions!
I am replacing covers in my own lounge to use for samples and they are all in tones of green. So I took a photo of the ones I have made so far. Then I used topography in Paint Shop Pro to bring out the tones.

I may play about with this photo some more to see what happens.