1. If you're on the fail screen, return to the Home screen of the app.
2. Turn off the bulb manually with the light switch, then turn it back on.
3. Check the firmware version of the bulb in the app. Tap on your bulb, then the Settings > Firmware Version. 
4. If you still have the option to update, try again. 
5. To delete your bulb and set it up again:
6. From the firmware's "Update failed" screen, tap the back arrow < then Remove Device. Then return to the Home screen, and tap the + plus sign > Add Device > Lighting & Control > select the bulb.
7. Once set up, your Bulb Color will have the latest firmware version.