After the site gave errors, I got an email with a link to the download.
This free plugin allows you to run Groovy (a Java derivative) code in FileMaker. You can do things that are not possible without a plugin. Many examples are included. One is a color picker far better than FileMaker has with examples of white text over the color, black text over the color, text in the color over white and grey, etc. It then returns variables r, g, and b with the values for the color chosen.
I won't review until I have done more with it, but it is an interesting idea, and the price is right.