the very first entry of a google search gives
https://www.amazon.com/gp/help/customer/display.html?nodeId=201601790the second entry gives
https://www.cnet.com/how-to/what-the-light-ring-colors-on-the-amazon-echo-alexa-mean/Solid blue with spinning cyan lights
The device is starting up.
All lights off
The device is active and waiting for your request.
Solid blue with cyan pointing in direction of person speaking
Alexa is busy processing your request.
Orange light spinning clockwise
The device is connecting to your Wi-Fi network.
Solid red light
You have turned off the microphones on your device. Press the Microphone button to turn on the microphones.
White light
You are adjusting the volume level on your device.
Continuous oscillating violet light
An error occurred during Wi-Fi setup. To learn more, go to Your Echo Device Doesn't Connect to Wi-Fi.
Spinning blue light that ends in a solid purple light
Do Not Disturb is enabled. To learn more, go to Use Do Not Disturb for Alexa.
Single flash of purple light after an interaction with Alexa
Do Not Disturb is active.
Pulsing yellow light
A message or notification is waiting for you. Say, "Play my messages" or "What did I miss?" To learn more go to About Alexa Messaging.
Pulsing green light
You are receiving a call on your device. To learn more go to Answer or Ignore Calls on Your Echo Device.