I also struggled with this and solved it.
for non-rgb colors using the white light, you must be in “color_mode: color_temp” instead of “hs”
supported_color_modes:
- color_temp
- hs
color_mode: color_temp
The rest of it was pretty straight forward.
I set the light in the scene UI and then just modified the YAML to change color_mode.
My full scene YAML:
light.eb4734acebb254704b5hab:
min_mireds: 153
max_mireds: 370
supported_color_modes:
- color_temp
- hs
color_mode: color_temp
brightness: 255
hs_color:
- 0
- 0
xy_color:
- 0.323
- 0.329
color_temp: 370
friendly_name: LAMPTAN jarton Bulb CCT+RGB 11w
supported_features: 19
state: 'on'