I have hue bulb, I want to change start temperature to 2000 kelvin. But HA want a value 153-500?
What is 2000 kelvin equal to in that scale?
That is the mired scale. Are you sure HA doesn’t support Kelvin for the Hue bulb?
A quick google around suggests that to get the mired value of a kelvin temperature you divide it by a million.
1000000/2000 = 500