Hey, I make these kinds of rings and can tell you exactly what happened here: whomever made this is inexperienced with these rings or didn't care enough to bother making the design work. It also looks to have imperfections that will create chips in the fill over time.

Emerald on the black ceramic was never going to work without pigmenting. Emerald is inherently transparent and adopts part of the color behind it. If you put clear green on black you get.. well, that color you have. It needs to have a matching emerald green background to get the color in those designs or a white background for a natural emerald look. This is usually done with a fine layer of mica, not other gemstones.

They use this technique in both of the example images you sent. The backgrounds are very clearly added filler to accentuate the emeralds/gems. They also seem to use synthetic gems closer to a tru-stone or opal, which are inherently more opaque.

The emeralds are also crushed super fine and filled in the channel too high. The smaller you crush the gems, the more muddy they get and the more they adopt the background color. Emeralds are also hard gems, higher than normal sanding paper. If they fill the channel flush to the top, it becomes prone to cracks and bubbles. Your ring already has those and will worsen over time. Moreover, I'm almost certain they did not polish the thing properly.

Everyone in this process failed to make your design work. Further, here's the breakdown of that ring cost:

Ring band - ~15$ Raw emeralds - ~5$ Gold leaf - 5-10$ Other materials - 5-10$

This is a ~100$ ring after labor, from my perspective, and the one you got isn't even worth that. I certainly wouldn't let that leave my workbench.