I encountered something similar on 24 March 2015 in a mussel bed:
There was an amazing diversity of colors in the bubbles among the foam.
And as before, I was fascinated by the rapid color changes and motion in some of the bubbles:
You can follow the movement of an "eddy" in a green bubble in the next two pictures. (The images were taken ~1 second apart.)
And watch how the large bubble at the bottom of the next picture changes over ~14 seconds.
A wave came and washed this foam away...otherwise I could have watched these bubbles for a long time!