I think I have the marble near the center pretty round now - at least it is better. I'll take a look at it again when I work on the marble on the left side of it. It may need a bit more work.
The marble on rightside, near the bottom was looking rather flat to me - it is the one with all the bubbles in the glass. I think it has a more rounded appearance now and that was done by just redirecting some color and lines. Did you notice you can see the bottom of the cut glass votive reflecting all the colors in the marbles too?
I've put the work from last night next to what I have done tonight to make it easier to compare exactly what I have done. You can see how the marbles are taking form with color, lights and darks. Not every reflection or highlight was made by white. I've used light blues, greens and grays and then next to those highlights I've placed darker colors to make the highlights pop. It is amazing to me how little globes of glass with streaks of color and bubbles, that seem to be frozen in place, can be so beautiful.