From this page: https://docs.puri.sm/Librem_5/Troubleshooting/LEDs.html
| Color | Description |
|---|---|
| Red | The phone is charging. |
| Red (flashing) | There is a problem with charging. |
| See below for advice. | |
| Green | The U-Boot bootloader has started running. |
| Green (flashing) | A boot-loop in the bootloader. |
| See below for advice. | |
| Yellow (red/green) | The bootloader has started the kernel but there is insufficient power to continue. |
| See below for advice. |
The above is from the troubleshooting page but you also have
| Color | Description |
|---|---|
| Blue | Notifications (when the screen is locked): received SMS, XMPP, Matrix message, or a missed call, system notification like updates. |
| Red/Blue (Purple/Pink?) | The phone is charging and you received a notification |