Quote - "What was the base material you started with?"

Plain white. The material is really simple. Color is plain white, transparency is 85%, reflectivity is 15% and the highlights have what I described. Everything else is just the default.
Maybe I should have also increased the slider of color transmitted light so that the shadows are colorful too but I couldn't find any reference photo where I could see shadows of bubbles and so I wasn't sure if the shadows are colorful or not.

I'm glad that my image inspired you. :-)