Ligth brithness does not work in scripts, but in GUI

Folks,
I run
Home Assistant release (hass --version):
0.33.4

Python release (python3 --version):
Python 3.4.2

Component/platform:
Raspberry PI all in one installation
light.domitech_smart_led_retrofit_kit_ze27eu_level_4_0 where I can change brightness in the HA GUI:

Try to activate a slider bar for the brightness. I tried to run a script which will swith the light on with a brightness of 10%. Seams not to work as I got errors. Also looks like that brightness is only supported for a HUE? Is this correct or how can I switch the light on with brightness 10 or 90?

when you click on the bulp that the brightness does appear

alias: Evening TV
  - service: light.turn_on
    data:
      entity_id: light.rv
      brightness: 155

I just noticed the hass version. You might want to consider updating. Depending on your configuration, there will likely be lots of breaking changes so make plans for some downtime while you fix configuration issues. The longer you wait the harder it will be.