Bonjour DABO
Yes, that's possible.
You can set your desired color in the app for the LED to illuminate. In this case, it would be blue.
To have the LED turn yellow from 08:00, you can go to the web interface > Nightlight > and select your desired time when the LED should turn yellow.
To illuminate the LED in yellow, set the "Color" slider to 60°.
Example:
Turn On at: 08:00
Turn Off at: 20:00
-> The LED will stay yellow between the specified times, and after 20:00, it will revert to the color you directly selected in the Dingz app.
Best regards
Sandro