Zigbee Phillips Hue brightness and temperature missing

I’m currently trying to control my Phillips Hue White/Ambience (Color, E27) via the Webthings gateway. My setup: RaspberryPi Webthings image + TI CC2532 as a Zigbee dongle + Webthings Zigbee adapter. Works perfectly fine! I managed to connect the bulb, turn it on and off and change the color.

Now what is missing is the brightness and temperature button. Any ideas how to get them? Through the Phillips Hue app, connected via Bluetooth, I have full control.

Many thanks in advance!