I got a Dropdown helper which includes the name of the lamps (lamp.xy) . Choosing/Dimming and turning the lamps on/off works, but when trying to change the color temperature nothing happens.
Even when choosing the lamps manually and not using a helper didnt work (homeassistant/z2m_ikea_styrbar_4button_remote_white2.yaml at ee0780409e2179a131494c4fe7e044e1a0e90d95 · rvdr/homeassistant · GitHub)