I think, based on a quick Yahoo search, that you could get your colors to shine a little better. While it may be true that our computers and cameras may not be able to produce true neon colors, there are many colors in the search results on yahoo that show up much brighter than your listing. I agree, play with different lighting and background. I think the photos, especially the closeups, with your fingers as the background take away from the color of the earrings. Be creative; take a look around at how others display earrings. See what you can come up with to showcase your beautiful designs.
ETA: do an Etsy search for "neon earrings". I think there are some good examples of how much better your color could be