Make sure your lights are on the LIFX Cloud then follow these steps:
1. Open the Alexa app and go to Smart Home in the Menu. Choose, Get More Smart Home Skills, and search for LIFX. Authorize your account with the Skill.
2. Close the authentication page and tap discover devices. After a few seconds your lights will be displayed under Smart Home in the Alexa app and you can optionally group them for Alexa here (hint: Alexa groups are separate from your personal LIFX groups).
3. Say “Alexa, turn my lights… On” or “...Off”. That's it!
4. Save your favorite colors as a scene in the LIFX app (tell me how) then ask Alexa to activate it any time: “Alexa, turn on My Pink Scene”.
Download the LIFX app for your preferred device and connect with Amazon: