Here's what I got.

You were right. I upped the light and there's color inside the sphere.

I don't know why but I used a regular sphere and still got lines. Another thing is that I used IOR 1,1 and your light meter just disappeared for some reason. It's exactly beside the flower. I rendered 3 times with different positions and I still can't see it.

Funny thing is that I forgot to turn cast shadows off in the sphere and still got color???