The current yaml language upgrade of #homeassistant changed from color_temp to color_temp_kelvin. Why doesn't Spook bring them all up for repair? Currently the automation dies.
Quickfix: go to "File editor", open automations.yaml STRG+F "color_temp:" click on + enter at replace "color_temp_kelvin:". Now click on "replace" at each hit. If you are brave or fearless, click on "all". It worked for me. Don't blame me if it's not working for you.
Viper539