We used the code from GitHub user HerrRausB to generate complex animations in the NeoPixel ring. You can download his code from GitHub. The code is nicely documented and has editable parameters that can be customized to fit your project. Huge thanks to HerrRausB!
Once you have the sketches how you want, you will need to upload the code to the Gemma. Please follow the instructions on the Gemma introduction guide to get your Arduino IDE setup with the Gemma. Once you have that sorted out, you will need to push the reset button on the Gemma and then hit the upload sketch button(the arrow icon next to check mark) in the Arduino IDE.