Turn on only white in light card

Hi all,

I’m using a KNX actuator to control a rgbw led strip and I have the following behaviour:

  1. colorwheel to red -> strip is red
  2. turn off strip via button -> strip is off
  3. turn on strip via button -> strip is red
  4. colorwheel to green -> strip is green
  5. turn on white via the slider -> strip is green + white
  6. colorwheel to white(center) -> strip is ugly white (red + green + blue)
  7. turn on whote via the slide -> strip is ugly white (red + green + blue + white)

How can I turn on only white?