Thanks for bringing your question to the community! If you’re seeing flashing Cyan, it’s an indication that the Core is able to join your Wi-Fi network, but unable to connect to successfully complete the handshake with our server to get online.
There’s another active thread, located at the link below, that has helped some of our other community members solve this issue.
Hopefully you can match the symptoms you’re seeing with other members with the same problem, and get your Core up and running! Be sure to email us at hello at spark dot io if you’re still having problems.
Will @ Spark