Interesting… I’m always interested in CA, as I don’t see what I think it is in my lens collection, so I jump at the opportunity to explore it. Here’s a 500% zoom into @s7habo’s image (left) and the raw in-process in rawproc, linear RGB (right):
I assume it’s the yellow edges to which you refer. In the linear RGB, you can see the starting point for that shading, but it’s faint.
On the linear RGB in rawproc, I toggled on and off the lensfun CA correction, that just accents it. I backed out to look at the whole image, and observed that the shadows are splaying in the opposite direction, indicating that the sun is illuminating the branches on the side of the yellow coloring. So I think what’s going on is that the branches have a sunlit component along their edges, and the color correction is amplifying it, to the point of haloing it past its boundaries.
Thanks for pointing that out; I like to pick at such to understand it. What I’ve asserted is just my conjecture; would appreciate others’ takes on it.