I'm sorry; I don't see it. I've seen hundreds of date pickers and color pickers and alerts, and they look very similar. The visual design language of the web co-evolves across millions of sites. There are only just so many ways these things can be done. I prefer to have a web filled with familiar, usable components, rather than every designer trying to make the same control somehow novel.

Unless these folks wholesale copied your html and CSS source code, I don't think you need be getting upset about it. The "look and feel" cases between Apple and Microsoft settled this issue in the 90's - it's not protectable.