What is what does it mean when alexa is yellow?

Here's what it means when your Alexa device displays a yellow light:

A yellow light on your Alexa device typically indicates that you have a message%20or%20notification. This is most commonly a reminder from your Amazon%20shopping list or an upcoming delivery notification.

To clear the yellow light, simply ask Alexa: "What are my notifications?" or "What are my messages?". Alexa will then read out the details of the notification, and the yellow light should disappear. If it's a reminder, Alexa may ask if you want to mark it as done, snooze it, or cancel it.